reFX has released a demo version of Nexus for Windows and Mac OS X (the download contains both). The full version has just been updated to v1.0.9 too.
Demo limitations:
- After 5 minutes volume fades out / in.
- After 15 minutes Nexus quits (you have to restart it).
- You cannot save patches.
- You cannot render audio.
- Settings are not saved with your song.
- Reduced library (a good mixture between file size and quality).
- No skin import / expansion import.