Tim set a simple, but very much real-world challenge; write an app that determines the top 10 most popular blogs from his Apache access log. It should be fast and readable, with a subtext of illustrating how "language X" copes in terms of parallel processing and utilizing "wider" (many processor) systems.

Since PHP natively doesn't support multi-threading (well), Harry opted to go with an approach using curl_multi_exec instead. There's two pieces to the puzzle - the mapper to grab the information and extract the data and the reducer that makes the calls to grab the information from the log files.

If you want to generate JPEG images with a limited file size, and at the same time you do not want to sacrifice too much the image quality, you have to find an approximated value for the quality factor that leads to an image with a file size near the desired limit.

The JPEG Reducer takes this approach, providing you with the ability to give it the quality you want and have it approximate the closest values to convert it to. There's a brief code example included as well. Check out the full documentation for the class here.