Improvements continued with the release of Linux 2.2 in January 1999. A
port for UltraSPARC systems was added. Networking was enhanced with more
flexible firewalling, better routing and traffic management, and support for
TCP large window and selective acks. Acorn, Apple, and NT disks could now
be read, and NFS was enhanced and a kernel-mode NFS daemon added. Signal
handling, interrupts, and some I/0 were locked at a finer level than before to
improve symmetric multiprocessor (SMP) performance