Apart from the new web browser, Syllable 0.6.6 focusses on improvements in POSIX support, running virtual machines in Qemu, and better installation and upgrade experiences. Obviously, it also comes with a massive list of bugfixes and patches. Looking at the changelog, there are a few interesting notes: for instance, experimental support for installing Syllable off USB media, a new mouse preferences panel, and a newer version of SDL.
"This has been the longest, most difficult release we have ever overseen, and I'd like to say a huge, massive thank you to Kaj and Anthony for their help and support, to every single person who has contributed to making this release happen, and of course to everyone in the community to continuing to support Syllable even when things have been very quiet," Vanders, lead developers of Syllable, said in the announcement.
You can get this new release via the download page.