I shipped a couple of things on Flash back in the day but it was staggeringly bad software — random crashes, various heisenbugs where changes in one area would affect unrelated functionality in other modules, etc. — and while it cost something like $800, it was completely unsupported: I filed a number of trivially reproducible bugs with reduced test cases but never heard anything back until the next release came out and they sent automated suggestions that the bug might be fixed so I should buy a full-price license and find out.
And that was Jobs argument, that it was too resource intensive. Predictably though, now that annoying crap moved to "newer" tech (javascript) and now we can't disable it as easily or without as little consequence. Just as resource intensive though...
The pivotal point was that flash would break this stronghold by allowing rich applications that are reasonably self-publishable. (Excuse me while I go rinse that sentence out of my mouth)
Remember back in 2007 when Apple first told developers that to develop for the iPhone, they’d need to build WebApps for Safari? Well, that really was the plan. At the time, Jobs said:
The full Safari engine is inside of iPhone. And so, you can write amazing Web 2.0 and Ajax apps that look exactly and behave exactly like apps on the iPhone. And these apps can integrate perfectly with iPhone services. They can make a call, they can send an email, they can look up a location on Google Maps.
And guess what? There’s no SDK that you need! You’ve got everything you need if you know how to write apps using the most modern web standards to write amazing apps for the iPhone today. So developers, we think we’ve got a very sweet story for you. You can begin building your iPhone apps today.
https://9to5mac.com/2011/10/21/jobs-original-vision-for-the-...
Jobs hated Adobe:
According to the biography, Jobs’ longstanding animus toward Adobe helped form his vision for Apple’s tightly controlled mobile environment.
In 1999, he was flatly denied when he asked Adobe to create a version of its popular Adobe Premiere digital-graphics software for the Mac. Adobe also wouldn’t rewrite Photoshop for the Mac’s operating system, even though Macs were popular with designers.
“My primary insight when we were screwed by Adobe in 1999 was that we shouldn’t get into any business where we didn’t control both the hardware and the software, otherwise we’d get our head handed to us,” Jobs said, according to Isaacson.
The two companies go back together even further. Apple invested in Adobe in 1985 and they worked together early on. But Jobs, who in Isaacson’s book comes off sometimes as vindictive and brusque as he was innovative and inspirational, told Isaacson that Adobe went downhill after founder John Warnock retired.
“The soul of Adobe disappeared when Warnock left,” he said. “He was the inventor, the person I related to. It’s been a bunch of suits since then, and the company has turned to crap.
https://edition.cnn.com/2011/11/09/tech/mobile/flash-steve-j...
Only when jailbreaking and custom apps got very successful, Apple introduced official app support and the appstore.
I bounced around a lot between the three OSes at that time, and Flash was bad enough on the other two that I would almost automatically reach for Windows when I had to use it.
https://www.apple.com/newsroom/2026/06/app-store-ecosystem-r...
Then again, they chose to use those exact words in their webpage, so you decide how large a grain of salt to take.
Why not? Flash was objectively an awful experience on mobile, and the iPhone was entirely about good UX.
> I'm pretty sure Apple strategists knew the value of the gate-kept platform, the app-store revenue stream.
Initially the iPhone didn't even have an app store. They wanted everyone to make HTML5 apps.
Those that think using Godot or Unity is the same, never did Flash games.
Notably, there was also a MusicWorks. Both Mac-only. But like EARLY Mac-only.
/dates me
gold
JavaScript build system layer cake and "web standards" are a million times harder than just drawing some stuff, maybe writing a simple function, then building a static file that can be embedded anywhere and even downloaded. You have to spend so much time setting up any flash alternative, and the "standards" are worse.
I hate Steve Jobs for killing Flash and Adobe for being such awful stewards of one of the most amazing web technologies.
Kids growing up today have no idea how magical Flash was. It was like Roblox or Minecraft for web.
Websites are still inferior to Flash of the early 2000s. It's taken decades and they can only mimic a fraction of its power. And none of its ease.
The “everyone hates Flash” stuff came later. It served a purpose for quite a while and people loved it. Newgrounds was a place of magic.
I do miss kongregate tho.
The entire browser ecosystem started out closed source. Even JavaScript was written to interact with closed source Java Applets.
> Flash was a constant embarassment of RCEs vulns
Browsers still are the goto target for contests like Pwn2own. It is almost like inviting the entire world to run untrusted code on your computer is not a great idea, no matter how many security buzzwords browser makers like to throw arround.
That is completely, 100%, untrue and not remotely historically accurate. WorldWideWeb (the first web browser) was public domain. Lynx came out in 1992. Mozilla was open sourced in 1998. There was never a time when the "entire" browser ecosystem was closed source. It certainly didn't start that way.
> Even JavaScript was written to interact with closed source Java Applets.
No, it wasn't. From WP (https://en.wikipedia.org/wiki/JavaScript):
> Netscape decided to add a programming language to Navigator. They pursued two routes to achieve this: collaborating with Sun Microsystems to embed the Java language, while also hiring Brendan Eich to embed the Scheme language.
> The goal was a "language for the masses", "to help nonprogrammers create dynamic, interactive Web sites". Netscape management soon decided that the best option was for Eich to devise a new language, with syntax similar to Java and less like Scheme or other extant scripting languages.
> [...]
> The choice of the JavaScript name has caused confusion, implying that it is directly related to Java. At the time, the dot-com boom had begun and Java was a popular new language, so Eich considered the JavaScript name a marketing ploy by Netscape.
Some people might have used it for the purpose you claim, but that's not why it was invinted.
And the reason for that two language approach is given in the linked source:
> We aimed to provide a “glue language” for the Web designers and part time programmers who were building Web content from components such as images, plugins, and Java applets. We saw Java as the “component language” used by higher-priced programmers, where the glue programmers—the Web page designers—would assemble components and automate their interactions using [a scripting language].
Earlier sources clearly state that Java was intended as the primary language and JavaScript merely acting as glue.
> Flash was a constant embarassment of RCEs vulns
I wonder if anyone has done an analysis of Flash versus Javascript (or other browser technology) vulns over their respective lifespans.
But it did suck, and badly. It crashed the browser all the freaking time, often hard enough to crash the whole OS. (“But the OS shouldn’t let that happen!” True, although even with that said, it was in the short list of common apps capable of crashing that badly. It was almost a talent.)
Flash was horrid. While idea was fine, the implementation was terrible. No mobile OS could have run it solidly and without sucking batteries like no tomorrow. Flash in the right hands could have been nice. We’ll never know because that never happened.
By the time mobile could run Flash, it was too late. Between Apple & Adobe, it had no shot of making the transition. But before that, Flash was pretty amazing.
For all the many reasons people might dislike Apple, they were 100% in the right on this topic. Flash needed to die. It got everyone to collectively push the web standard technologies ahead into something way, way better.
Sorry, that's simply not true. The tech was ahead of its time. The implementation was intuitive. Only developers and Steve Jobs hated it, because Flash made it way too easy for anyone to make something fun.
Sometimes good products happen despite bad technical foundations.
Let me introduce you to itch.io[0] where, in fact, people bang out HTML5 games at a rate that will stagger your eyeballs.
(Even me, a resolute "backend-only" dinosaur managed to use a HTML5 game engine to knock something out playable in an hour or two.)
[0] https://itch.io/games/platform-web - ~689k results
People hated flash. Even non techies.
Flash was very cool, at first, then it got used for WAY too much stuff that had no graceful degradation so you were stuck waiting a few minutes for an animation to load so you could see the content stuck behind flash.
Billions of people enjoyed using Flash for games, video, music, and animated entertainment.
Do people love Javascript and HTML5, or do they like streaming entertainment?
Do gamers love Unity, or do they love playing fun games, some of which are made with Unity?
I played games on every Windows from 3.1 and up (and MS-DOS before that), but I'm not pining for the days of Windows ME despite how much fun I had on that machine.
People used Internet Explorer to run all their Flash entertainment, but nobody is arguing that IE was loved even though it was part of the flash stack for a huge majority of users.
Notably, Flash is dead, and no one is arguing that we bring it back.
If I never have to sit through a flash loading bar gating an HTML website with a completely unnecessary splash page, you won't find me mourning. (yung'uns: this was a thing. If you wanted to go see a website sometimes you had to sit for a while so a dumb flash animation would show and you could click through to the actual HTML content. Jobs did you a favour)
People loved flash for what flash was good for (creative toys) they disliked flash when certain sites started making it the core of the navigation etc.
When people are nostalgic for flash it's for finding random toys from other people who weren't "IT people".
for the younguns https://archive.org/details/joe-cartoon-frog-blender#
People hated it when apps were glitchy, when it wanted "constant" updates, or how they couldnt share a page because the entire site was some bloody flash applet.
Right up until enshittification kicks in and suddenly everyone cares and there are shouts of destroying the evil techbros who are poisoning the minds of our youth to buy a new yacht.
Can you imagine the situation if Jobs hadn't killed Flash? Most of the commercial websites required a Flash blob to deliver full functionality even back then in the early 2000's. Adobe never even vaguely pretended to be the good guys, they would have enshittified as soon as they possibly could, as hard as they possibly could (as they have done with the rest of their software). The entire web would be held to ransom at this point.
Being a binary blob is not a strong argument all by itself. chrome.exe, firefox.exe, etc. are also binary blobs. I have no love for Adobe, but that specific criticism is weak.
Is this a troll? What could an application do with Flash in 2005 that we can't do with a modern web application today (excluding the obvious answer of runtime vulnerabilities that allowed apps to escape the sandbox)?
Show me the JavaScript framework (or tool that exports JS) that you can give it to a middle schooler and have them make a cartoon with audio and moving images that they can draw themselves, while responding to user input. Have the exported artifact be consistent across all major operating systems and browsers.
Yeah, Flash was never replaced
I didn't get into flash games at all, but I used to watch Flash animations.
Like, for instance, Salad Fingers: https://archive.org/details/flash_salad-fingers
This was intended for a slow 2004-era computer with a 4x3 (probably 1024x768) display, where it worked very well.
But it's not 2004 anymore; things are much faster and screens have gotten a lot bigger. Here in 2026, Salad Fingers renders out fine at higher resolutions, and at different aspect ratios. It works great on my desktop at 1080p, without stretching [and with some probably-unintentional extra content on the sides]. It even works on my pocket supercomputer's 3200x1440 20:9 display.
Vectors are fun, and they scale as technology improves. The lines remain smooth and defined. And with Flash, that's a built-in: An unaltered 22-year-old digital animation still looks crisp.
For contrast, if Salad Fingers had been published on YouTube way back around that time, it would have been in chonky fixed-pixel 320x240. Maybe that would be as good as it would ever get unless it were rendered and uploaded at higher resolutions later.
This isn't my baliwick, so I've absolutely nothing to say about the ease with which these options can be created.
I mean, consider this: McDonald’s used to be fun and colorful. Now every McDonald’s is boring and gray. And, wait, every store is boring and gray! And flash had nothing to do with that.
I would be remiss if I didn’t post the most early-Internet-type thing I’ve encountered in a long time. Dungeon Soup.
https://m.youtube.com/@DungeonSoup
Once upon a time this would have been my favorite Flash cartoon series.
“Season one” playlist: https://youtube.com/playlist?list=PLSq76P-lbX8Ws6vgAAC2WhwSu...
In any case, take heart though. If we did it once, we can do it again.
Adobe could have retuned Animate to do it, but instead let it languish as a niche animation tool for some animation studios to use before trying to kill it.
1) macromedia ->
2) adobe ->
3) steve jobs
I think 2 was the root cause, not #1 or #3.
https://web.archive.org/web/20170615060422/https://www.apple...
That said, I wonder how easy it is to publish on apple? I think of xcode in sort of the same way sj complaining about adobe being cross-platform and slow.
But the only standard you need is WASM. All browsers support it. Use whatever you want to make it. In fact, Ruffle is just a WASM app.
(I agree that we're better off without Flash, but this particular problem is real and unsolved.)
It’s safe to say we all miss sites like Homestar runner, and I had a co- worker who generated many meme – worthy flash presentations of his coworkers, which were hysterical. however, flash generated security vulnerabilities on the daily, and unfortunately, these vulnerabilities were very conveniently cross platform. These vulnerabilities, which Adobe couldn’t, or wouldn’t, resolve resulted in many many lost hours fixing virus – and Trojan horse – infested PCs, Macs, and cell phones. Adobe never managed to sandbox flash at all.
I miss a lot of old flash content, and I’m sure many people miss the ease with which you could create interactive content for websites. The fault here lies squarely on Adobe, who wouldn’t fix the situation.
I can tell you how much tsc sucks off the top of my head but what I can't do is tell you to hit ctrl+enter in Claude desktop to play movie.
What kids know today is how magical Claude desktop and ChatGPT are. The deploy story is trivial. just give the AI the key. We can judge someone for being dumb enough to do that, but unless you're selling consulting services, it's not nice to laugh. if you are selling consulting services then let's talk sales channels lol
Somewhat mirrors my experience with all those rubbish non-PDF formats for digital document publishing, e. g. ePub: Often terminally ugly and utterly useless on top of it (not properly citeable, et cetera).
There is no way to get access to it. I don't mean the licensing cost is prohibitively expensive for an indie dev although I understand that to be the case as well.
There is no one to talk to. The email listed on their website does not respond to anything. Not even so much as a "Thanks for your interest" or a "We will get back to you".
I messaged a former colleague who worked there to try to see what the process is to get access to rmsdk. He said he tried to find internal docs about it and couldn't find anything.
I tried to find people on linkedin who might be associated with rmsdk and ask them and similarly found nothing.
Meanwhile publishers only distribute most of their titles with one of their known drm vendors ie Apple, Amazon, or Adobe. The other two are entirely closed off.
If this isn't anticompetitive trust behavior, I don't know what is.
I love my Kobo (clara colour) and really, if they just removed the Adobe reader, it'd be perfect. And yes, I've tried KOreader, but never switched to it because I like my Overdrive library books and Kobo Store.
The case mentioned where the CSS min() function is rejected is another place where bulk import of the extremely complex CSS spec is just not helpful. Ebook readers aren't evergreen browsers after all.
With EPUB compatibility issues CSS should always be suspect number 1. Using "modern" CSS features and complaining about missing flex boxz grid, etc is a web developer's mindset.
Just because EPUB shares some of the stack with the web doesn't mean they perfectly overlap (or even should).
Hardly any e-ink embedded e-reader devices use a browser for rendering, they all use purpose built HTML/CSS parsing and rendering toolchains, are baked into firmware and updated once in a blue moon. (If you're interested look at koreader's crengine or Crosspoint reader which runs on an ESP32!)
The blog post reeks of overly confident AI prose. But don't be fooled.
https://pine64.org/devices/pinenote/
More expensive and less out-of-the-box software, but straight to the point on device ownership/what kind of software you can run, fewer strings attached.
[EDIT]
Great experience blogs on the PineNote
https://shom.dev/posts/20250308_pinenote-day-one/
https://shom.dev/posts/20250406_a-pinenote-only-5-day-weeken...
The Kobos don't limit what you can do with them either, you can sideload alternative e-reader software like KOReader that improves on the built-in reader functionality.
Basically if you want a "product" to use right now and still want to tinker, RM gives you ssh access to a system you can tinker with. RM2 has the best community support for now though.
PineNote works... but yes you will have to be ready to tinker. It's heavy and think but powerful, all the way to having a browser, audio, microSD, etc.
Meanwhile the PocketBook Verse Pro just works, no tinkering, but also tiny and not get for sketches IMHO.
If, like me, you clarify your thoughts by physically writing (not typing) or sketching, then the ability to do so without distraction, moving a piece of text of the page, changing the position of a box in a complex diagram... then it's definitely worth the price IMHO.
This note was in the original comment, did you read it? The fact that it is $400 (more expensive) and has less out of the box software is literally mentioned to alert people to that.
> The Kobos don't limit what you can do with them either, you can sideload alternative e-reader software like KOReader that improves on the built-in reader functionality.
This is patently false, the latest Kobo Libra Color is using secure boot which completely locks out custom development:
https://www.mobileread.com/forums/showthread.php?t=363175
So much so that QuillOS which used to be Kobo focused rewrote to support the PineNote
https://github.com/Quill-OS/quill
The point is to buy hardware that is built for you to freely modify and fully own, from the start.
My post was to make sure everyone knew the PineNote was an option, because I certainly did not know it until someone on HN made me aware.
Could you maybe make your point more concrete? Are you attempting to completely dissuade people from using the PineNote because it may not be easy to side load apps to it on hacker news?. Obviously different people have different propensities to do hacking, and some may not be able to afford the PineNote due to how expensive it is, but it's not clear what the goal of your comment was.
If your goal was "invest in Kobo instead of PineNote", I disagree with that. I'm not interested in investing (whether money or time) in an ecosystem that is just going to rug pull me eventually, over nickels and dimes.
BTW for those who agree, another great option is XTeink -- very hackable, and I've bought one myself:
And there's a Linux phone out there which looks pretty encouraging too:
https://furilabs.com/shop/flx1splus/
Graphene is likely still the easier more polished option, but it's great to have options these days.
Thanks for the link on mobileread. I was not aware of current development in direction of secure boot / chain of trust.
Not OP, but when I was looking for an e-reader, I looked up the Pinenote. I could not find easily a lot of information on its software state. I could find a lot on Kobo hacking. I notably found https://anarc.at/hardware/tablet/kobo-clara-hd/ and this motives me to get a second hand Clara HD for less than 100$. It was way cheaper than starting with 400$ and unknown software state.
I hadn't heard of the Pinenote before looking at your comment, so I looked at the site and saw some things that made it seem unfit for purpose as an ereader. I made my comment because I was interested in hearing your impressions if you were using it as a daily driver.
> The point is to buy hardware that is built for you to freely modify and fully own, from the start.
Personally I view stuff like this as a nice-to-have, not a must-have. If it means I can't have an interface where I can buy books and then download them to my ereader, or I can't have an iphone app where I can read books and have my progress synced between my ereader and my phone, or it's unstable, or the battery life isn't good, then I would rather go with the Kobo. I understand that different people have different priorities, but those are mine. Stuff like this is why I'm interested in hearing more detailed information about what exactly the tradeoffs are for going with something like the Pinenote.
> This is patently false, the latest Kobo Libra Color is using secure boot which completely locks out custom development:
I think you can still sideload KOReader on them, but that's a shame that they're making it harder to replace the stock OS entirely. I hadn't heard about that prior to now so thanks for bringing that up. I only have a Sage I bought a few years ago.
I updated my original comment to include some more personal blogs with first-hand accounts. They're not mine but worth linking to for others!
I haven't bought a PineNote yet, but it's probably going to be my choice for that size of Tablet. I opted for a Xteink instead and have been very happy with it.
> Personally I view stuff like this as a nice-to-have, not a must-have. If it means I can't have an interface where I can buy books and then download them to my ereader, or I can't have an iphone app where I can read books and have my progress synced between my ereader and my phone, or it's unstable, or the battery life isn't good, then I would rather go with the Kobo. I understand that different people have different priorities, but those are mine. Stuff like this is why I'm interested in hearing more detailed information about what exactly the tradeoffs are for going with something like the Pinenote.
I agree that there are certainly a lot of sharp edges to less supported platforms. I just think I'd rather get a Boox (and deal with Android/Graphene) or PineNote over the Kobo over the long term. Then again, my usage of very simple -- maybe I just don't read as much/depend as much on the ereader to the extent that others do!
> I think you can still sideload KOReader on them, but that's a shame that they're making it harder to replace the stock OS entirely. I hadn't heard about that prior to now so thanks for bringing that up. I only have a Sage I bought a few years ago.
Ah yes, AFAICT what you're saying is correct -- sideloading apps is not an issue as far as I could find, it was just the inability to have custom firmware/OS.
I was very disappointed in this, and I generally see it as a step towards locking down that will only continue. Would love to be wrong though as I was very very convinced I wanted a Kobo Libra Color earlier).
People that are happy with the Kobos as they are (and the bundled software/services) I'm sure will be happy to keep buying though, I think the market is certainly big enough for that!
The Pine projects are necessary and well-motivated, but the PineNote doesn’t strike me as a reader’s device, maybe a hacker’s or someone that wants an e-ink tablet.
[1] https://www.kobo.com/kobo-writing-life/blog/our-commitment-t...
Kobo's added features on top of ePUBs are nice, and their renderer is much better than Adobe's standard pipeline.
So, it's a free upgrade with a terrific local library added on top.
I remembered one particular master student on the verge of tears trying to compile his LaTeX thesis draft, he took the “write and think about formatting later” too literally and was trying to compile it for the first time very close to the deadline.
Whether a looming deadline changed the perception about that, we don't know ;-P
> Create your new ByteBooks ID using the same email address that you used for Adobe ID
Seems sold mostly.
TBH i've being using an ePub reader that i occasionally had to edit ePub files so i get rid of the superfluous styling that made it either not work or show things weirdly/wrong and i've heard comments from others that a bunch of files i had no issues with personally were unreadable for them, which makes me think that unless you really and absolutely need any fancy formatting (i.e. math stuff that can't just be made images - and you really tried to!) then you should stick with the most basic HTML imaginable - things that not even IE4 would render (too) wrong.
And in turn, since i doubt this will ever happen, i sometimes ponder making an "epub reconstruct" tool that attempts to reconstruct epubs so that they use the simplest HTML/CSS :-P (ideally configurable for maximum compatibility).
I've often thought about figuring out a subset that operates fast on any computer and sticking to that for any web pages I make. If someone figured that out for epub, it would make it much, much more useful.
Got a refurbished pocketbook in the end and very happy with it, it reads all imaginable file formats and I can just send books to it via email or cable.
I have never seen someone explain the adobe software so perfectly. Using any adobe software is exactly this.
I used EPublish for my first novel, Means and Motive, just published here, DRM-free: https://www.amazon.com/dp/B0GYCZJVGX
So far I haven't heard of compatibility issues, so I think EPublish has hit the sweet spot of EPUB targeting. I agree, however, that it feels like the old days of targeting IE6 on the web. Old readers still exist out there, so we have to aim for the lowest common denominator.
The best ebook format I have ever experienced is .txt and just let the software figure out where the text needs to go.
Everything else is better with koreader and it’s super easy to install alongside nickel. And it works very well with calibre + the kobo plugin.
But isn't that kind of the point of epubcheck? It's surely not intended to validate all of CSS, it's intended to validate that an epub will work... and not working on Kobo devices (probably #2 manufacturer of ebook readers?) is a major issue.
The standard exists, it is the responsibility of both the producer and consumer of ePUB files to adhere to the standard.
Though these days I have to spend more time worrying about EAA and ADA compliance than anything else.
According to the author, Kobo uses CSS from 2013. A quick check with an AI says RMSDK supports CSS 2.1 and parts of 3.
So it's not that the renderer is broken, it's that he believed that epubcheck actually checks against devices and the versions of CSS that those devices support.
This is exactly the issue with test tools: the test tool tests to a spec, but the platform is the gold standard. If you don't like it tough shit.
These days I usually get 90% of the way on google docs, then do the final editing on LibreOffice which can add things like tables of contents and cover image, if it opens on Kindle, Kobo and Calibre I consider it job done.
Ebook producers really should be forced to either drop drm or adopt a cross-platform standard.
The publishing industry never got its head out of... some dark place. We've been able to buy mp3s without drm for ages, but somehow books are different.
Easy to be dismissive, but IP violations can cost a large company hundreds of millions.
IP lawyers are more important to many companies than their software developers.
If you doubt that, check to see who gets paid more...
This is blatantly wrong.
In a perfect world, RMSDK wouldn't exist in the first place and Adobe would have gone bankrupt and become history at least 10 years ago.
https://en.wikipedia.org/wiki/Thoughts_on_Flash
https://web.archive.org/web/20170615060422/https://www.apple...
I’ve switched to kobos (Clara HD) and I’ve had to for years. It’s chugging along (had to 3d print a replacement power button a couple months ago), I can run koreader no problem and use calibre with the kobo plugin. And the default rendering engine in kobo’s firmware does actually typeset the text: no ragged edges!
I'm very grateful for this information and it explains why I've avoided epub opting for pdf over epub as my reader software is old.
I'm am very much on the side of supporting backwards compatibility. It reminds me of the times the M$ used to upgrade their doc standards ... where if one hadn't upgraded, well bad luck.
PDF is not somehow immune to this either — a non-conforming implementation could similarly break what are meant to be forward-compatible extension points by raising an error on an unknown stream or object instead of (as required by the standard) ignoring it.
PDFs certainly can suck, more often those that will only work with abode's software and other viewers I've tried can not.
PDF is not nearly as pleasant under the hood. It's down right lovecraftian.
https://b3n.org/psd-is-not-my-favourite-file-format/
or in the code:
PDFs can be painful as well, more often it's then using abode's pdf viewer, but it's far less common for me. There was a time many years ago when I understood PDF structures better, back when I chose to manually edit and fix a couple of malformed PDFs.
Straight HTML, edit anything everywhere. Super slick.
The epub standard doesn't say what version of CSS must be supported. There were no guarantees modern CSS would work so I wouldn't call the renderer broken.
> illegal values, or values with illegal parts, are treated as if the declaration weren't there at all
So a conforming implementation would ignore that max-width property declaration, not raise an error.
And those earlier versions of ePub which defined a required subset of given CSS standards? The forwards-compatible parsing rules were part of their subset.
Ignore != Fatal error
As such, whenever I get my hands on an .epub file, I go to an online converter, convert it to a .pdf file and nuke it from my system. Then the .pdf gets opened in my FoxIt.
It looks like not a whole lot has changed in that space -- the readers are still the gate for what you can do with the format. Who's available to make a CanIUse for epub readers, to shame them into compliance? (only partly /s)