it gives some kinds of output format,e.g. regular text , xml or others you can implements form the interface. sometimes you want to print message, printf is too simple, but some opensource logging system is too complex, then, you can try this, its a just enough logging system. default provides for you these methods:

trace, info,debug,warning,notice,error,wassert,fatal,output
and all the code is platform Independent, support win32 and linux, had tested with vc6.0, vc7.0, vc8.0, vc9.0, and gcc3.2