P-CAD even had a dongle-caddy where you could plug in I think about 7 of them into to unlock different modules.

I will check if I can find an image of it.

EDIT: here is an old listing of it: https://www.ebay.com/itm/187748130737

Sadly the lid isn't open so you can't see what modules are installed.

> I think sometime in the late 1990s FlexLM switched from dongles to "hardware identifiers" that were easily spoofed; honestly I don't think this was a terrible idea since to this article's conclusion ...

Starting in '97 I worked on some software that used Elan License Manager (elmd) that then moved on to FlexLM in a major release.

Requests for, and problems with, licensing were a considerable source of support tickets but I'm sure it also drove a reasonable amount of sales as customers wanted to play with component X but were prevented from doing so by a lack of license.

When we were acquired by IBM we replaced the licensing code with lawyers and (threats of) audits. It didn't seem to harm the revenue. The product is still being maintained and sold.

> ... if you could reverse one you could reverse the other.

I can confirm it was quite easy with gdb to either skip past the license checks or, in the case of Elan licensing at least, call the license generation function from within the binary to generate whatever licenses for whatever features you liked.

The "hardware identifiers" were a nightmare too. I ended up writing some code that would pull all of the necessary information (primary MAC, IP address, hostid for Sparc machines, hostname, etc) and give it to us in a base64 encoded blob, we also grabbed some CPU and memory information that proved quite useful in seeing how the software was deployed.