I still remember myself sitting in front of my double tape deck stereo system, playing a copy of a tape I borrowed from my guitar teacher back and forth. It contained 'Europa' from Santana, and I tried to figure out how he made these weird sounds. Later, when I learned to play the electric guitar with the web as my tutor, I found out one can bend a guitar string to increase the pitch gradually.. (which was of course not part of my classical guitar education)
Since the rise of the internet, guitar has become the most accessible instrument for non-educated musicians (if it wasn't already before). Together with the large amounts of free instruction material and tabs or sheet music out there, these pieces of software are now making life easier than ever:
Guitar Pro has long been the one thing you needed for accessing most of the tab resources on the web, and it still is. It is not that expensive, so if you really want to learn to play the guitar it's a must-have! Since the recent sixth version of the software however, the sound engine has evolved a lot, so that it is also capable of transforming your compositions into reasonable audio tracks, or making backing tracks for your favourite shred solos. Very recently, they also introduced the option of buying additional soundbanks (especially useful for the keys and drums in my opinion), making the software a true competitor for VSTi plugins. If you're still not sure, there are other options to access guitar pro files though.. but the genuine software remains the best. By the way, did I mention that it is available for Linux, Mac and Windows. My favourite place to find guitar pro files is still ultimate-guitar.
Guitar Pro Viewer first was an extension available in google chrome but has now turned into an app that allows quick access to all famous songs you know. It is in fact an implementation of AlphaTab, which allows searching songs in the songsterr database. Definitely the most easy option for learning that famous riff to show off at the next band rehearsal!
TuxGuitar is a simple free alternative to guitar pro since it is compatible with most of the guitar pro files available on the web (*.gp3-5). The development is however not that active since the latest version already dates from end 2009. If you find a tab, you can try to read it with this piece of software. Composing is of course also possible, which AlphaTab and Guitar Pro Viewer do not allow.
Go PlayAlong offers combining tabs (including guitar pro files) with MP3 backing tracks and SoundFonts. It is a bit more flexible than guitar pro in that perspective, but in view of the recent developments of guitar pro, I suspect it will only be a matter of time before such options become available too.
Guitar tabs on your mobile!
Guitar Partner Pro is an Android app, that can read guitar pro, powertab, and TuxGuitar files, and Guitar Pro has an app for your iPhone, iPod touch, or iPad!
Development doesn't stop of course. While Cloud services are emerging everywhere, the guitar tablature market cannot lag behind. Noteflight is however the only service I currently know off, but for sure, others will emerge soon. The basic account is free, so give it a try! It also allows embedding your compositions into your own websites. Recently the tablature options became available for their free plans, so it is open to guitar players now. Very easy if you use multiple computers with multiple operating systems, since it is entirely web-based. This is the future, for sure!
If you're after high quality sheet music, LilyPond is the thing you need! What LaTeX is for science, LilyPond is for music. Hard to learn, but definitely worth the effort! Many music notation programs are enabling compatibility with the LilyPond format for this reason, which is of course cross-platform, and free for everyone. Only drawback is that it's text-based, as LaTeX..
Frescobaldi is a solution to this, as it is a kind of GUI for using the LilyPond language. Another option that is quite similar is the Denemo.
Power Tab Editor is probably the second most-used tablature software out there. Many powertab files can be found on the web, and it is completely free. However, guitar pro files are more common nowadays, and this software is Windows-only.. which makes me not want to use it.. But anyway, it is still available, and a lot of tabs can be found for it.
General composing software
MuseScore is definitely an interesting piece of free software. Tablature support is however not available yet, but they're working on it. Again cross-platform, so a very promising piece of software.
Some other options worth linking to:
As you can see, playing tapes back and forth is not necessary any more since quite some time now. You can take your tabs with you everywhere you go, or store them in the cloud to make them accessible from anywhere. I'm curious what the future will bring..