Microsoft Tools to Save InfoPath Forms as HTML
Using the HTML to XHTML Conversion Tool
The Microsoft Office InfoPath 2003 Software Development Kit (SDK) HTML to XHTML conversion tool allows you to convert regular HTML into well-formed XHTML that can be edited in an InfoPath form.
https://msdn.microsoft.com/library/en-us/ipsdk/html/ipsdkusingthehtmltoxhtmltool.asp
Using the Downlevel Tool
The Microsoft Office InfoPath 2003 Software Development Kit (SDK) Downlevel tool is a script-based command-line utility that is used to generate an HTML downlevel view of an InfoPath form or the XML document that an InfoPath form produces.
https://msdn.microsoft.com/library/en-us/ipsdk/html/ipsdkUsingTheDownLevelTool.asp