Your not going to find an open source map software. Map services require a lot of proprietary data. Guys driving around and putting in data on new roads and such. There are a few open source projects that use Tiger data files (which come from the government), but that data is not nearly as accurate. The raw map data is just not freely available.
Using google's map api's is probably as close to open source as you could get.
Dale Beams wrote:
I am looking for a MapLinx, Microsoft Maps or ESRI Buisness Map Replacement in OSS Software. Is there any such beast out there? On-line services will work as well if they provide the same functionality.