The class libraries are grouped together in the assemblies they belong. Each directory here represents an assembly, and inside each directory we divide the code based on the namespace they implement. In addition, each assembly directory contains a Test directory that holds the NUnit tests for that assembly. The nant build file for an assembly creates two versions of the dll for that assembly. One version is a "full" dll. The full dll contains (almost) all of the classes, regardless of how complete the classes are. The name of this dll is the normal name you would expect, like "corlib.dll" or "System.dll". These full dll's are created in the /mcs/class/lib directory. The other dll which is built is a "restricted" dll. The restricted dll omits incomplete classes that would prevent the NUnit testrunner from actually running the tests. These restricted dll's are created in the Test directory of their respective assembly and named with a "_res" suffix. So, for example, the NUnit-testable dll for corlib is /mcs/class/corlib/Test/corlib_res.dll. The final dll which is built is the one which houses the actual NUnit tests. This dll is built from all of the classes in the Test directory and below, and is named with a "_test" suffix. So, for example, the NUnit tests for corlib are in /mcs/class/corlib/Test/corlib_test.dll. This dll is also linked with the restricted dll found in the same directory. * Missing implementation bits If you implement a class and you are missing implementation bits, please put in the code the word "TODO" and a description of what is missing to be implemented. * Tagging buggy code If there is a bug in your implementation tag the problem by using the word "FIXME" in the code, together with a description of the problem. Do not use XXX or obscure descriptions, because otherwise people will not be able to understand what you mean. * Tagging Lame specs Sometimes the specification will be lame (consider Version.ToString (fieldCount) where there is no way of knowing how many fields are available, making the API not only stupid, but leading to unreliable code). In those cases, use the keyword "LAMESPEC". * Coding consideration Use 8 space tabs for writing your code (hopefully we can keep this consistent). If you are modifying someone else's code, try to keep the coding style similar. Please use code that looks like this: bool Method (int argument_1, int argument_2) { if (argument_1 == argument_2) throw new Exception (Locale.GetText ("They are equal!"); if (argument_1 < argument_2) { if (argument_1 * 3 > 4) return true; else return false; } }