I don't want to get in to the rbenv vs RVM debate - they're both good tools and it's an issue that has been done to death. I linked to five articles in the post, and you can find many, many more with a simple Google. My personal motivation for switching was that bundler's overridden 'cd' function includes some commands that fail, which is fine under most circumstances but it breaks as soon as you use 'set -e' in bash. We spoke to the author and he said he said that RVM wouldn't be 'set -e' compatible in the foreseeable future.