Some obscure free software tools that I've found. Where the Debian package names differs from the binary, the package name is in brackets .
(ack-grep)
grep for source code
tail -f using inotify, which means the kernel informs you when the file grows, instead of polling every few seconds
a minimalist FIFO and filesystem-based IRC client. Creates a directory tree with server, channel and nick name directories. In every directory a FIFO in file and a normal out file is created.
tail, for RSS feeds
(iprint)
$ i --help 45 0x2D 055 0b101101 '-' 45 0x2D 055 0b101101 '-' 104 0x68 0150 0b1101000 'h' 101 0x65 0145 0b1100101 'e' 108 0x6C 0154 0b1101100 'l' 112 0x70 0160 0b1110000 'p'
top, for network interfaces.
Credits