i did some finding and found theres a project markdown sharp which is used by stack overflow?
Open source C# implementation of Markdown processor,
ah. i found the answer.
Markdown markdown = new Markdown();
markdown.Transform(txtEditor.Text);
docs: Markdown.cs
/// <summary>
/// Transforms the provided Markdown-formatted text to HTML;
/// see http://en.wikipedia.org/wiki/Markdown
/// </summary>
...
public string Transform(string text) { ... }
i found out abt this reading the inline docs. in php, web call it phpDoc but in C# i wonder whats it called.