It's been a very long time since there was a good free version of Pro Tools - it was back on Mac OS9 or Windows 98/ME.
However at NAMM 2015 Avid have announced a new free version of Pro Tools to coincide with the release of the commercial 12.0 version - they're calling the free version Pro Tools First.
Here's the promotional video released by Avid - the premise seems to be that they want aspiring musicians and producers to start out on a free version of Pro Tools rather than a cracked copy of their (and others) software:
One interesting aspect of this new free version of Pro Tools is that it allows you to save your projects in the cloud making them available to you anywhere - such as when you go to a friends place or even to a recording studio.
This free version will allow you to record a maximum of 16 tracks - either simultaneously or one at a time - although this is too limiting for professional recordings these days, it's certainly enough for recording basic demos.
It comes with Avid's built in Xpand!2 software synth as well as time stretching and a pretty good MIDI editor/sequencer.
Rather than being a standard free version, Pro Tools First is based on the 'Freemium Model' which allows you to buy a wide range of both effects and instrument plugins to enhance your music productions.
Avid haven't given a precise date for when you'll be able to download Pro Tools First, but it will become available for Mac OSX and Windows 8 sometime soon at apps.avid.com/ProToolsFirst/.