Kai's Power Soap – SOAP.EXE
Most commonly, soap.exe isntalls with Kai's Photo Soap. This program originally bought by MetaCreations was recently sold to ScanSoft. Kai's Power Soap 2 restores old or damaged photographs, adds stunning special effects, prints to popular formats and papers, and exports pages ready for the web. More information and support can be found at http://www.scansoft.com/photosoap/.
A file called Soap.exe can be downloaded with the Microsoft Developer's Network article "SOAP: Using ATL Server to Build an Asynchronous SOAP Client in Unmanaged C++" found at http://msdn.microsoft.com/msdnmag/issues/02/04/SOAP/. If you're not a developer, you're not likely to have this on your system.
Safe
ScanSoft