I want to enhance my browser-based web application with functionality that enables management of local files and folders. E.g. folder tree structures should be synchronized between local workstation and server via HTTP(S).

I am aware of security-related limitations in browser-based applications. However, there are some techniques that "work around" these issues:

• Signed Java applets (full trust)
• .NET Windows Forms browser controls (no joke, that works. Just the configuration is horrible)
• ActiveX

My question is: What do you use/suggest, both technology and implementation practice? Key requirement is that the installation process is as simple as possible.

Thanks for your opinions!