Here is an overview of my free Magento modules with links to the blog posts describing them in detail.
You'll also find my modules on GitHub.
Cron Scheduler Module for Magento
Removes old cache entries in your Magento instance and supports some more cache related functions. This can be run regularly as a scheduler task.
Make your Magento store fly using Varnish!
Demo extension for the Magento/Varnish proof-of-concept.
Advanced Template Hints for Magento.
Automatic Versioning of JS and CSS files for Magento.
Asynchronous Cache for Magento.
News interface for managing website / store groups / store views.
Adds "ifconfig" and "unlessconfig" to blocks, actions and references in layout xml.
Configure your custom design fallback level (e.g. add further fallbacks).
Uploading product images to Magento using Aoe_FilePicker
Find out why your Magento store is so slow!
Class Path Cache for Magento Autoloader