I have written a project on .NET 4 and am currently in the process of allowing it to run on Windows Phone as well. I am using HtmlAgilityPack, a well known library which allows Linq queries over HTML, and am only using the LoadHtml and Linq interfaces it provides.
Having converted the class libraries from .NET 4 to PCL (Portable Class Library) with support for .NET 4 and WP8, I cannot seem to use the HtmlAgilityPack library anymore. Is there a way to allow HtmlAgilityPack to function correctly under a PCL project or is there a variable alternative with a similar Linq interface that does work as intended?
EDIT: HtmlAgilityPack provides 9 different versions, none of which are compatible with PCL. None of them resolve dependencies from the references. For some versions, it may appear that it does but upon usage an error will be thrown with the usual 'cannot load, unresolved dependencies'.
EDIT #2 Since it easy to miss a small comment, I'll update this answer with the solution I came up with. I extracted what was needed for basic functionality and implemented the missing components to make everything work. The result is here https://github.com/Deathspike/HtmlAgilityPack-PCL
You've asked and answered your own question - haven't you?
The HtmlAgilityPack does not support use with Portable Class Libraries.
At best you'll need to look at porting/migrating the specific functionality you require in a way that will work on the platforms you are using.