#70, #71 - This is a nice and cheerful letter-play, but I'd prefer you to design an abstract/pictorial mark for us. Just like you've done with so many of the logos in your profile. Complexity, ligtness, software, user-friendliness - just a few terms that could help.
#275 - nice, but it wouldn't work in one-colour version and very small (favicon, an icon in the footer of our products)
#258, #259, #276 - I like these. Clean and modern. I prefer #258 over the remaining two. #276 has some dynamics and energy involved, but I favour stability and growth in #258. Those tiny red elements in #259 don't work for me...