I would suggest for the first sentence, “The IMAGE team of the GREYC laboratory is happy to invite you to celebrate with us the 10th anniversary of G’MIC, our open-source (CeCILL), generic and extensible framework for image processing.” (What “its” refers to is not clear in the existing English version.)
Instead of “ad vitam aeternam”, I’d suggest “ad infinitum”, if you feel it also reflects your intent, because “ad infinitum” is more commonly used.
(I made a few typographical changes already, but felt these should be suggested rather than just edited in place.)