DAD is a Windows event log and syslog management tool that allows you to aggregate logs from hundreds to thousands of systems in real time. DAD requires no agents on the servers or workstations. Correlation and analysis is driven through a web front end.
C# Logger
This is a logging tool similar to log4j for java. The tool is designed to handle debugging, information and error logging. Currently only windows event logging is supported however multiple logging targets are planned for future releases.