Module SDK: 

Heidrun is a module based hotline client, which means that people can make modules by their own in a very flexible way using the Heidrun Module SDK. A module can include features like simple bot features to complex file handling features. Almost all of the current hotline protocol features are already wrapped into ObjC methods to make it extremely easy to send/receive hotline transactions but you may also write your own wrappers. Documentation, a project template (PB) and the code for all the default modules are included in the SDK.

Download Heidrun Module SDK: Heidrun Module SDK 0.7 (1 MB)

Click here for a list of modules and their sources done with the Heidrun Module SDK.