LogViewer is a MS Windows .NET application that display logging datas. It's like the unix 'tail'. It can read a file or listenning over a TCP socket. Use regulars expressions to Hide, Rewrite, Colorize lines of log. Have a look at Screenshots section.
It's got useful functionality, but the usability is quite poor. If you have one particular log that you are constantly looking at, it's probably ok. But if you want to look at a few logs of the same type and quickly highlight important lines, it takes way too much time to get set up, unfortunately.