Berlin is the code name for the Cerowrt 3.8 (3.9?) build which is currently (May 2013) under development.
Modena is the code name for the current CeroWrt 3.7.5-2 build, created in February 2013. You can read about it at the main Wiki page.
Sugarland (CeroWrt 3.3.8-26) was released on 18 Sep 2012, and is the first release to include CoDel code. It is listed here only for the historical record, since the the Modena (3.7) builds incorporate all its features and offer significantly improved performance.
The bql-smoketest builds provided a good improvement to the buffer bloat problem from November 2011 through February 2012. However, all their major improvements have been implemented in the Linux 3.3 kernel. You can read the BQL series release notes. bql-smoketests: http://huchra.bufferbloat.net/~cero1/bql-smoketests/
About the OCEAN CITY release. In the latter half of 2011, we had hoped to release a build with grand goals. This release was to be named OCEAN CITY. But reality set in, and it became obvious that we could not meet these goals. The rc6 build is the culmination of the Ocean City release. Download the stable release: http://huchra.bufferbloat.net/~cero1/cerowrt-wndr3700-1.0rc6/
Any remaining references to an Ocean City on these pages are being changed to align with the more important goals set out above. The OCEAN CITY page lists obsolete information.
The following may be incomplete or outdated.
BloatLab 1 (isc.org)