The newest build of Chimera is 0.2.3. You can download it from the following locations:
What's New (0.2.2 -> 0.2.3)
Chimera 0.2.2 was compiled with correct ATSUI (ATSUI with kerning and ligatures enabled). Yes, we have that working, but as you saw, it slows things down substantially. Chimera 0.2.3 returns to the fast ATSUI as the default. This pref will eventually be exposed in Advanced preferences (along with the ability to use Quickdraw as well).
The gamma correction regression present in 0.2.2 has been fixed in 0.2.3.
The form controls are now Aqua. This includes button, checkboxes, radio buttons, textfields, listboxes and menulists. Most importantly menulists now function! :)
Some more crash fixes also made it into 0.2.3.
Enjoy! Dave (firstname.lastname@example.org)
What's New (0.2.1 -> 0.2.2)
Chimera can now open URLs sent to it from other apps, so you can now make Chimera your default browser and not have it sit there looking stupid when you tell it to load something. ;)
Text Zoom has been implemented, so you can now increase and decrease the font size used in a Web page.
Chimera now obeys the new minimum font size pref, ensuring that Quartz-rendered fonts don't fall below the typical anti-aliasing cutoff point. Quartz rendering has been improved. In addition to being speedier, it now has fixes for printing and for text spacing.
Chimera now has a bookmarks toolbar. Like the Mozilla Classic personal toolbar, Chimera's toolbar can wrap to multiple rows and supports pages and folders.
Bookmarks management has been improved. You can now specify where you want to create a new bookmark. You can now create new folders. The sidebar tree widget has been enhanced to support more keyboard navigation (left/right arrows to open/close, return to launch, delete key to delete, etc.).
Bookmark groups have been fully implemented. When adding a bookmark with multiple tabs open, you have the option of bookmarking all the tabs as a single group. Use this feature to load bundles of pages in a single click!
Background tab loading will now work. Background tabs will now refresh properly if left unattended.
Chimera has complete build instructions on mozilla's Web pages (under the code name ChimChim). You can find those instructions here. Be aware that the downloadable build listed above contains numerous patches to Mozilla that have not yet been accepted, so any builds that you do will not be as stable or as performant as the downloadable build above.
If you have questions about building, use the chimera mailing list or hop on to #mozilla, and someone can help you out.