recommendation for offline Markdown renderer (for GitHub .md)?

Anyone got a strong recommendation for an offline Markdown renderer which can at least do a passable job rendering GitHub's .md style? grip uses GitHub API, contacts the server on every render, seems to not even cache CSS files... Also!: GitHub supports inlining section files (very useful for reducing file size/ dividing one large file) with this: <file name="section_2.md"> So having that work with an offline renderer would be gold™...