Last OpenAT version and related update

Hi to all.
Please, I would like to understand the following:
a) which is the last OpenAT version?
b) is it downloadable and at which address?
c) there are necessary firmware update to perform while installing a new OpenAT version? (I have a Fastrack M1306B and Integra M2106B)
d) therefore, there is some documents/manuals update?

Thanks too much in advance for your reply