Two days ago Ken Smith announced the release of FreeBSD 7.2, a release improving on FreeBSD 7.1 with some added features and updated software. This happened just days after OpenBSD's new release of version 4.5, their 26th release. Even DragonFlyBSD released a new minor revision that day. Of course, this was all a day after the release of NetBSD 5.0. I bet these guys agreed on a shared release date or something. All three BSD-based operating systems are open source, free to download from their respective websites.