Tablatures is a guitar and bass tablature editor.
Tablatures is compatible with PowerTab, which is a well-known and widely adopted tablature editor for Windows systems. Thus you can share your music even with those members of your band that don't own a Mac! Moreover, you can easily find thousands of song transcriptions in this format on the net. Tablatures can also import most GuitarPro 3-5 tabs.
With Tablatures you can also export your tabs in MIDI format, or follow the playback on-screen to help your learning process.