Question: I am developing an App where I would need to perform HTTP Request using C#.
Had in been PHP, I could use the HttpRequest class. Which class or group of class is best matched for the PHP HttpRequest by which I could make GET and POST Request.

Answer: 
See [QScintilla](http://www.riverbankcomputing.co.uk/software/qscintilla/intro). It has Javascript highlighting and (auto-)completion support built-in.
Try KatePart of KDE:

<http://kate-editor.org/about-katepart/>

To quote:

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> KatePart is a fast and feature-rich text editor component with many advanced features. It implements the KTextEditor interfaces, a common interface collection for text editor components in KDE, allowing it to be selected as the editor in applications that lets the user chose from different implementations, and it can use KTextEditor plug-ins.
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> KatePart is originally based on code from the KDE 1 richtext editor widget, but has been almost completely rewritten over the years. It is the default text editor widget in Kate and KWrite and also the default to display text in Konqueror. A lot of other applications use it as text editing component, too, like KDevelop.
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