You can check the alpha page http://xhip.net/alpha/
which hasn't been updated in quite a while.
The latest thread is Xhip Synthesizer v8.1 (alpha & RC)
The remaining things that need to be done for Windows and Linux version 8.1 include:
- Removal of remaining "control" background bitmaps and replacement with self-drawn text and backgrounds
- Improvements to the Linux file browsing dialog (show hidden files, confirmation boxes, some code restructuring)
- Minor GUI tweaks like alignment of LEDs, text and icon offsets in waveform selectors
- Improvements to font kerning at larger font sizes (like eliminating the space between --> hyphens)
- The basic beginning of the skinning system which will enable minor tweaks like adjusting menu colors and fonts
Other than that, the current versions are finished "almost v8.1" as-is.
The MacOS version needs to be re-built from the current source and updated. I've already done this but I haven't tested it enough yet. It works well, and if anyone were interested I could upload the latest alpha to the alpha page (but I won't replace the release until later after v8.1 RC stage.)
Since the GUI is still missing on MacOS it means the improvements are mostly pointless, so there is no very significant difference between the current r974 and the newer r1112 except that the new alpha includes the "preset library" feature. This means the new version includes embedded presets and writes a "default" init state upon first loading without one present.
Apart from the initial load the MacOS version is identical since you can't access those features through the GUI anyway.