If you decide to use GeoServer to deploy your Web Services, you will find that part of the process includes creating an SLD or Styled Layer Descriptor for portrayal of the data you intend to publish.  A natural symbology for such layers is an ESRI layer file format.   Using this format initially presented a problem, though; creating an SLD for data with a complicated symbology scheme, such as a geologic map, is not trivial using XML editing software-- even if you have a template to work from.  Many times, conversion from RGB to Hexidecimal is required for each entry in your symbology layer.  Even if one uses a built-in formula converter in Excel (or from various websites), a large amount of hand entry is still required.