In a recent post the Aura PHP blog compares the "lightness" of two different micro-framework-oriented packages - Silex and Aura.Web_Project (of the Aura framework project.

Too many people, including the Silex article author, use absolute terms like “light” and “heavy” and “bloated”, instead of relative terms like “lighter” and “heavier” and “more bloated” and “less bloated”, to describe software. Any time someone uses an absolute term like that, you need to ask: “Compared to what?” [...] don’t know if the measurements in that article are valid or useful for defining “what makes a microframework” but they do provide a basis for comparison. I understand that some people think “measuring (size|lines-of-code|number-of-classes) is stupid and it doesn’t matter!” Maybe it is, maybe it’s not. [...] So, let’s go with that article and use its approach to make a comparison between Silex and Aura.Web_Project to see if my earlier claim, using the terms and measurements outlined by the Silex post author, is accurate.

The rest of the post outlines the steps that were taken to perform the measurements, the tools used check things like memory usage and the results. They compare things like:

• Total Package Dependencies
• Total Disk Usage
• Total Class Count
• “Actual Usage” Class Count
• “Actual Usage” Non-Comment Lines Of PHP Code