Wavefront .obj libraries?


I have a reasonably simple problem as I’m using Poser to create CGI art. Poser uses a combination of their custom file formats with the Wavefront .obj file format for creating 3D models. The principle is reasonably simple as the Poser files link to materials and groups within the Wavefront file and what i’m trying to do is make a simple tool that can transform these models in slightly different ones by adding or removing new materials and groups. And I want this tool to be as universal as possible so I can use it on both my PC and Mac.
Both the Poser format and Wavefront formats are basically text files. I don’t think there’s a C# parser for those Poser files but as the Wavefront format is a bit old already, I was expecting to find some useful C# libraries for Wavefront. Libraries that can be used to and and remove pieces from a Wavefront file without modifying or reorganising the structure. But I can’t find any good ones.
I don’t need to display the Wavefront files because that’s not the main problem. I need something that will transform them. As they’re basically just plain text files, I could write my own code and just add or remove stuff but that feels as if I’m reinventing the wheel. So, any suggestions?
Btw, is anyone even working on 3D modelling with the .NET foundation?

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