Xplode is a multiplatform IDE designed for the Plasm language. IDE stands for Integrated Development Environment, a program that embeds an editor and a connection with the compiler. So, you can edit your own programs with the editor window, and then compile your programs, or better, make the MzPlasm Interpreter evaluate your geometric definitions or expressions.
The source code is the same for all platforms (actually, there's just a little OS-dependant code). The binary distribution for MacOSX and Windows include the Qt library, since they're not included in any operating system version. The Linux binary distribution does not include the Qt library as any distribution ships the library. Check your distribution web site for the proper package. For a complete overview about software licenses, see the license page. For more information about the Qt Library, refer to the relative page.