I started the new Community Project ZAPP_INTEGRATOR. The first version can start transactions on the WebAS ABAP using the SAP GUI for Windows (WinGUI). Ranganath Prasad published a tutorial on the SCN Wiki: CRM WebUI - Launching transactions in GUI for Windows. My project has the benefit that it also supports starting the WinGUI in the same window and also does include support for Single Sign On (SSO) using the SAP Logon Ticket.
Currently the ZAPP_INTEGRATOR project supports to start a transaction on the WebAS ABAP using the SAP GUI for Windows (WinGUI). You can select between the Structured Storage Document (SSD) and the SAP Shortcut File (SSF) technique. The great benefit of the SSD is that it can seamlessly integrate into the current application window. Unfortunately SSD requires ActiveX and so it does only support Microsoft Internet Explorer.
This is an example how the SU01 Transaction can be included into a BSP Application: