The task is to build a command line tool in Java to checkout/update code from open-source hosting platforms such as github, sourceforge, googlecode. The downloading should be parallel, that is: allow multiple projects to be downloaded at the same time. We assume that the open-source project checkout/clone tools such as git, svn are already installed and available in PATH. The tool should work on both Windows and Linux. The skeleton of the tool (the main classes, the command line argument parsing, sql connection facility) is already written, only need to fill in the querying database part and the threaded downloading part.