These AddIns can be downloaded off my downloads page.
The "Hello, World!" AddIn. Demonstrates the steps required to build an AddIn, how to implement both the IAddInConnector and IAddInConnector2 interfaces (of Gregor.AppCore.Extensions), and how to make an AddIn available to scripts.
Indigo also decorates, through the Gregor.Core.MacroAttribute .NET custom attribute, a Shared Public sub as a "macro" (CIndigoConnector.TestMacro). This is allows AddIns to expose routines that the user can invoke via the GUI, with support of a parameter dialog.
This one adds the MS WebBrowser control to WebEdit's work space. The following techniques are used:
DataDocs enables WebEdit to talk to OLEDB data sources via ADO.NET, and show/edit documents from databases. Extensiblity highlights include:
The name is taken from the unofficial longhand of RSS - "Really Simply Syndication", though correctly, it's "Rich Site Summary". This AddIn lets the user configure RSS sources. These are basically just URLs to XML files, using the newer RSS schema (I don't know the exact version numbers). All items in a given feed are shown in a list, an can be opened in WebEdit.NET.
While this AddIn does not teach you any additional techniques, it's an example of how two AddIns can cooperate in a way unforeseen by the developer of either AddIn. While that latter claim seems to indicate medical problems rather than technical features, what I'm trying to say is that the WebBrowser AddIn offers a context menu entry to open a given URL in a web browser window, which the Syndication AddIn shows for any given feed item. The result is a feed reader that uses a graphical browser.
See Also: Extension Points | WebEdit.NET API | AddIns