Here you can download pre-compiled Cryptonite binaries for Windows and OS X.
NOTE: these are all 64bit binaries, Cryptonite does not support 32bit systems.
New releases can now be found on GitHub: github.com/pallas1/Cryptonite/releases
Information for Windows version:
Download the db48 file if you either don't know about the wallet db version you have, or if you need compatibility with the old wallet database format. Choose db61 instead if this is the first installation or you don't need compatibility with the old wallet db format.