I just saw that letsencrypt.org strating project 'Open SSL for all' but On the other hand already many good and paid SSL aviable on merket. So what your opinion?
I think Let's Encrypt could be hugely important. For a lot of smaller hobby sites, for example, an SSL cert is a rather expensive commitment. It puts SSL within reach of everyone. Another interesting thing is that they're setting the expire time on issued certificates to be three months or so. They're hoping as a result that people will develop tools to automate the renewing of certificates. Shorter times helps improve internet security overall: https://letsencrypt.org/2015/11/09/why-90-days.html I haven't tried it myself, but I intend to look at it in the future.