CMS.NET

I have a couple of sites that I created for my city. I used various platforms for this: Joomla, WordPress, SMF, Pligg, Elgg. And everything would be fine, but some sites have become popular, people like them. And it is pleasant to me when they thank me for the work done. And I want for them to improve these sites, but I can not, because I am programming in C #. I try, I pick, I understand PHP, but nothing good comes out. And replaced with a decent written in C # I have not met. I have already decided to write myself, but I think I should consult with the copyright, but eight people know good CMS.