RubyMine displays the Welcome screen when no project is opened. For example, when you run RubyMine for the first time, or when you close the only open instance of a project. From this screen, you can create a new project, import, open, or check out an existing project from version control.
Use the Configure menu at the bottom to configure your working environment and the Get Help menu to open help topics, tips of the day, and the default keymap reference.
If you previously opened projects in RubyMine, you will see a list of these projects in the left pane of the Welcome screen. You can click any project in the list to open it, start typing to find a project, or remove any project from the list.