MapServer is an Open Source platform for publishing spatial data and interactive mapping applications to the web. It supports numerous OGC standards including WMS, non-transactional WFS, WMC, WCS, Filter Encoding, SLD, GML, SOS & OM and can read data from a massive number of raster sources such as TIFF/GeoTIFF, EPPL7, and many others via GDAL and vector sources such as ESRI shapfiles, PostGIS, ESRI ArcSDE, Oracle Spatial, MySQL and many others via OGR. It is consistently one of the fastest and most configurable online mapping engines in the world, blowing many commercial mapping engines out of the water. We have been developing MapServer solutions for years and can provide a system to suit your needs. We can also help you convert your existing mapping server over to this free alternative. MapServer is licensed under an MIT style license & runs on all major operating systems.