I'd prefer that a LispWorks user answer, but there are quite a few interesting features, such as:
reply- tree shaking and small binaries (±5MB a GUI app)
- the CAPI cross-platform and native GUI toolkit
- mobile platforme runtime (iOs, Android)
- its Java interface
- its KnowledgeWorks system for "rule-based, object-oriented, logical, functional and database programming"
- more?
ps: today we maintain a list of pretty decent libraries: https://github.com/CodyReichert/awesome-cl/