MemoryWell is powered by Ruby on Rails, so you'll need to make sure you have Ruby installed.
MemoryWell uses PostgreSQL, so you'll need to get that up and running as well. Here's a good soup-to-nuts tutorial for Mac users. In short, the easiest way to do this on a Mac is to install Homebrew and run brew install postgresql. Then run the following commands to get it up and running, per the instructions:
ln -sfv /usr/local/opt/postgresql/*plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
Once you've got PostgreSQL running, you can install the dependencies. From inside the MemoryWell directory (that is, this repo), run:
gem install bundler
bundle install
Now create the databases you need:
rake db:create
And you should be all set. Give it a whirl:
rails server
If all went well, you should be able to mosey over to http://localhost:3000 and see the site.