The IDE does not allow me to add source files in another directory to a project. This makes it more trouble to develop library modules. As it is, I have to copy the library source file into the project file in order for the IDE to see it. After making modifications to the module, I have to remember to copy it back to the directory where I keep all my library sources or else I will have two versions that don't sync up. I routinely do this with test programs that I use to develop the library module with.