Developing Achievo Extensions - Part 1 (Basics)

Part 1 of a three part series about developing Achievo modules can be downloaded here.
This guide shows you the basics of Achievo development. It shows you how you can add new features, using only a very small amount of code.
After working with this guide, you should be able to take the first steps to implementing your own extensions, allowing you to adapt Achievo to the needs of your organisation.

 Developing Achievo Extensions - Part 2 (Advanced)

Part 2 of the Achievo development guide, lately also known as 'the Pizza guide', is finished and can be downloaded here.
This part of the guide shows you how to implement relations between nodes and how to implement triggers. It also gives some hints on userinterface improvements.

 Developing Achievo Extenstions - Part 3 (Expert)

Part 3 of the Pizza Guide Series is not finished yet, but the first chapter can be downloaded here.

 Table model

Martine Groenendijk has contributed a table model (entity-relationship diagram) of the Achievo database. This model reflects the database of the current development version.
The model can be viewed as a large GIF.

 ATK documentation

Since Achievo is based on the 'ATK Toolkit', all documentation relevant for ATK is also relevant for Achievo development. You can find ATK documentation here.

 ATK Flag Reference

For people developing extension modules for Achievo, there's a page containing a quick reference for the node (NF_*) and attribute (AF_*) flags that you can use in your module.