how to include a gem if server dont suport it!

If you specify needed gems in environment.rb (config.gem ... ) then
there are rake tasks for unpacking the gems into your app. Things
might be more interesting with something like ruby since that has
native code ( the rake tasks can also build the gems for you but I
assume you access to a machine close enough to your deployment
platform that it can compile code that runs on that) and even more
interesting with one like rmagick since that depends on the
imagemagick libraries being installed.