If you’ve ever need to read and write Excel spreadsheets in PHP, there is an excellent library available called (unsurprisingly) PHPExcel. I have been using it for over a year in production systems to produce reports — people in the insurance industry still like to work with spreadsheets — and it’s saved a huge amount of time. On the rare occasions where I’ve stumbled across a bug, the developers have been quick to respond and issue a fix.
The code for the library is available on GitHub and licensed under the LGPL, so you can use it in closed-source commercial projects. I’ll be posting some tutorials for PHPExcel in upcoming weeks, so stay tuned if you want to find out more.