What's Flash projector? In brief, it's an application that converts flash files (SWF, FLV) to executable files (EXE). There are few such products in the market. For example, Flajector.
So how to create flash projector. The most important tasks you should to solve:
1. Embedding flash activex (ocx) in an EXE.
2. Working without accessing to TEMP directory. Another words, no temporary files are created during application life.
3. It should be compatible with all Windows versions: 98 and so on.
Sometime ago I found a good framework that helps to solve all these tasks. It's F-IN-BOX. There are few editions: Delphi Edition, DLL Edition, .NET Edition.
As soon as I know, Janus uses f-in-box .NET Edition.
UPDATE: Oh yeah, Flajector also uses f-in-box (DLL Edition, I think so).