Chrome is on the verge of definitly break compatability with NPAPI, and IE breaking with ActiveX the future of Java Applets is dark. Currenty we actively use a secure applet for out client organizations that enables their users to upload a bunch of files from their file system to our servers with the click of a button. The applet has full access to any configured drive, including network drives.
With the imminent death of the applet this functionality is going to be lost if we don't find an alternative. I have already tried to explore different solutions, including the chrome FileSystem API but that is currently only available for Chrome (http://caniuse.com/#feat=filesystem) and has limited access.
Does anybody know about an alternative to keep supporting the much appreciated functionality? Unfortunately we are obligated to support all browser down to IE8.
In light of the answer provided by Uly Marins I have researched the options suggested. Unfortunately these options weren't viable for our application, because the mayority of our users do not have sufficient rights to install third party plugins. Additionally the API is still in Beta which won't do any good in a stable production environment.
The main problem we wanted to solve was the abbility to delete files from the accessed folders. It seemed like one of the mayor goals of the removal of the NPAPI support was exactly to prevent this kind of possibility. Therefore we needed to reduce our goals to a simple solution that was still acceptable for our users, with the additional training on how to clear the selected folder manually (because most of our users are almost computer illiterate and needed to access network folders).
Long answer short. The requested solution is just not possible anymore and had to be replaced by a simpler solution and additional training.