- Custom built web parts
- An application in the _layout folder
- User controls and the Son of Smart Part
- ASPX pages added to a SharePoint Site
Read his article here.
The Kide have added some pros and cons for different ways on how to develop sites in SharePoint 2007 and WSS 3.0:
- Use the SharePoint Solution Deployment
- Develop on one farm and use Site Export/Import or Content Deployment
Full article here.