trueSpace7.6 is now free?

What's the reason behind this? I know software companies sometimes give away stuff but this version is only a version behind isn't it.

And what about this gamespace light?

Because Caligari was acquired by Microsoft, which decided in turn to offer the software for free. So it's not one version behind, you can actually download the latest one. The reason behind the acquisition was probably to integrate it with Virtual Earth, as shown on Caligari's homepage.

as far as i know, gamespace is non-existant now due to truespace being free.

Microsoft did the same thing when they acquired Creature House and gave away Expression 3, which went on to become Expression Studio.

They do this because they love you. ;o)