Redmine

Hi to all,

I want to install a package of Redmine on my ubuntu server.

I have read through the tutorial but can't afford to do it. In fact , putty gives me a shell where I am invited on a prompt.
When I type gem install bundler. the shell prints an erro => use apt-get install, it is normal !
Then I do this : apt-get install gem and it says it does not recognize gem but this works : apt-get install bundler. Can I start the install by using this option?