2.11BSD is the final version in the 2BSD branch of the Unix tree. It began as a full collection of the patches to 2.10BSD, but incorporated many of the new features of 4.3BSD. As the VERSION document says:
This would have been the third release of 2.10BSD, but since the filesystem has changed and a coldstart is required this release was instead called 2.11BSD.Since the original release of 2.11BSD, Steven Schultz has been maintaining the system, and incorporating many of the features from 4.4BSD into the system. This makes 2.11BSD one of the longest maintained versions of Unix.
This release incorporates all fixes and changes posted to the group comp.bugs.2bsd on the newsnet since 2.10.1BSD was released. Present in this release are several more missing pieces from the 4.3BSD distribution:
- the kernel logger (/dev/klog)
- the namei cache
- readv(2)/writev(2) as system calls rather than emulation/compatibility routines
- the shadow password implementation released for 4.3BSD
- a TMSCP (TK50/TU81) driver with standalone support (bootblock and standalone driver)
- a couple more network drivers have ported or made to work: if_vv and if_acc
- the portable ascii archive file format (ar(1), ar(5)) has been implemented.
- last, but most importantly, long filenames!
The files here come from the 2.11BSD area of the Unix Archive, and were donated by Steven Schultz. This particular snapshot of 2.11BSD is patch level 431, dated April 2000.