Does anyone know what font is this, I have seen it used frequently recently
Sorry to burst your bubble Sam but this is not Rotis SemiSerif STD. As Yves has already pointed out it “looks somewhat like Rotis SemiSerif” but it’s certainly not a match. My guess is that this is actually derived from Rotis Serif to begin with. Note the balled ends of the ’a’, ’r’ and ’c’, it would be much more difficult to add these to Rotis SemiSerif than to simply remove the serifs at the bottoms of the serifed characters. Beyond that the charactes have been squashed vertically with the curves of the ’a’ and ’c’ having been completely redrawn. I also suspect a stroke has been added to the arms of the capital ’T’. You can see what I’m yapping about visually below.

No problem. ;^)
The suffix STD only means it’s a Standard OpenType face, a typeface with a limited character set that doesn’t take advantage of advanced OpenType features. That’s purely technological and has nothing to do with the design. The suffix Pro stands for ’fat’ OpenType faces with extended character sets, like small caps, contextual ligatures, Eastern European accents, Cyrillic, Greek and so on. Read more about it here.
Pretty sure it’s a custom designed logo inspired by Rotis SemiSerif.
Captured from web.archive.org on 14 Oct 2008. view this capture