Tablature

Bucket o' Tab
Freeware tablature editor for Windows 3.1/9x. 4-7 strings. Includes MIDI support.
http://www.antisleep.com/bucket/

eTktab
Freeware ASCII tablature editor for Mac/Windows/Unix. 30 fretboard positions accessible by a single keystroke. 4-7 strings.
http://etktab.sourceforge.net/

Gootar's Guitar Tab Generator
Online open source tab editing program, uses regular text files.
http://www.gootar.com/tabber.html

Guitar Pro
A multitrack tablature editor/player for guitar, banjo and bass. Free demo. Import/export MIDI and ASCII. Links to Guitar Pro tabs.
http://www.guitar-pro.com/

MusEdit
Notation software for guitar/bass tablature (4-6 strings, alternate tunings), treble/bass/drum notation, chord diagrams, and lyrics in any font.
http://www.musedit.com/index.htm

Power Tab Editor
Guitar and bass tablature editor for windows. Freeware.
http://www.power-tab.net/

TabIt
Shareware program for creating, playing, and printing guitar, bass or banjo tablature and making MIDI files.
http://www.tabit.net/

TablEdit Tablature Editor
A program for creating, editing, printing and listening to tablature and sheet music. Multiple tracks, 3-12 strings, MIDI playback.
http://www.tabledit.com/

TabPlayer 6.0
Edit, play, print and write guitar tablature. Also features an MP3 player and a chord dictionary.
http://www.simoneperandini.com/tabplayer.htm

Tabs, Lyrics & Chords
Tablature editor/database for transposing keys and other tab operations.
http://www.tabslyricschords.com/

Web Chord
An on-line utility for converting ChordPro files to HTML, for viewing, printing or use on web pages.
http://webchord.sourceforge.net/