The past few months, the BIND 10 developers have been using a test-driven development model. As classes and functions are coded, corresponding unit tests are also coded to help verify the routines do what is expected -- with good or bad input providing correct results. Sometimes the unit tests are written before the new code or the tests are written soon after.
ISC recently improved its software support lifetime and End-of-Life (EOL) policies. Previously, ISC only provided public development and commercial support for the latest major release version and the prior major release version. Also the next older major release version became EOL six months after the latest major release was announced. (So for six months, three major versions are supported.)