• Letters to Theo (Pause MathJax)
• MathJaxWMD (Resume MathJax)
• SEModifications (allows linking to comments)
• My Downvotes (click twice to see the downvotes you've cast)
• Recent questions from my tags (use it from the front page for your particular stackexchange)
• symmetry code
• Rob John, the mean square, and his texerdoodle for the chat.
• More efficient use of space during editting