No quick overview matrix, unfortunately. Probably worth doing. Or maybe wait for the Rebol Alliance stuff :)
The gist of it, feature-wise:
- reboltech/mainline: baseline - rebolsource/community: mainline + 64-bit - saphirion: community + https + win32 view + bugfixes - atronix: saphirion + linux view + udp + linux CALL + ffi + encap + more bugfixes
Another factor is immediate platform support:
- mainline and community come with a relatively large set of build target platforms - saphirion currently has immediate build scripts for the big three (linux, osx, win32) and android - atronix currently has immediate build scripts for linux and win32
Ah yes, of course: in the features above, add "android view" to saphirion:
append saphirion android-view
Were those sources included?
The sources to the Android View port have not been released so far, as far as I'm aware.
Right, so the feature is not really there
There's a working APK you can download.
If that's sufficient or not for one to consider the feature to be there, is a personal decision.
Will they be in the Alliance version?
(I can't answer that; don't know.)
(Also: any omissions in the above list are purely due to me being forgetful or unaware. "rebolsource" is the only thing I can speak of with authority; the rest is purely my personal perspective. No misrepresentation of any of the above branches and their associated parties intended.)