If you do development work with different versions of MarkLogic, you've probably set up virtual machines. This has the advantage of complete separation among the different versions, but it can be a hassle. Matt Pileggi, part of MarkLogic's Vanguard team, put together the MarkLogic Version Manager. mlvm is an open source tool he uses to switch among versions of MarkLogic he has installed on his laptop, without using virtual machines.
Matt was inspired to write mlvm after using the Node Version Manager, which solves the same problem for working with multiple versions of Node.js. Right now, mlvm is a Mac-only tool, but Matt would welcome contributors to help with this or other improvements.
Matt's mlvm is a development tool that's off to a good start -- check it out on GitHub!