| Mathematics | Arxiv | Math/Physics preprints archives. | MathSciNet | Online math reviews. |
| MathWorld | An online math encyclopedia. | Geneology | Math geneology project. | |
| Linux | Ubuntu | Ubuntu Linux official website. | Debian | Debian Linux official website. |
| LinuxSir | A popular Chinese Linux BBS. | SULinux | Stanford Linux website. | |
| LaTeX | CTAN | Comprehensive TeX archive network. | CTeX | The best Chinese TeX website. |
| People | He, Jian | My friend at math dept. | Zhang, Yang | My friend at MIT. |
| Chen, Hui's blog | My friend at UT. | Li, Miao's blog | A wonderful physics blog. | |
| Wei, Zhen | One of my favourite webpages. | Ravi Vakil | Interesting stuffs in algebraic geometry. | |
| Pi, Liang | My friend at Univ of Wisc. | Lu, Shan | My friend at UIUC. | |