phpSysInfo is a customizable PHP Script that parses /proc, and formats information nicely. It will display information about system facts like Uptime, CPU, Memory, PCI devices, SCSI devices, IDE devices, Network adapters, Disk usage, and more.
The MathExt library was made to parse and calculate formulas of any complexity. It can easily be integrated into web applications. As developer you can set all kind of settings. You can even specify what commands should be available to the user.