Here's what the site says about it:

Rocket Network’s Central Server coordinates a master “arrangement” of audio and MIDI parts that are shared by each user in a session. Users “post” their audio or MIDI tracks to the session through their RocketPower™ audio software. Each “post” updates the master arrangement and then the Central Server distributes the new parts to other session participants. Whenever the user enters a session where there is a project in progress, the most up-to-date arrangement is downloaded directly into their audio application on their local computer. This eliminates the requirement for remote users to email (or snail mail) their tracks to each other, import tracks into their DAW, and convert the files to the required format for their DAW. Rocket Network even allows users to work cross-application and cross-platform. Rocket Network’s chat capabilities enable users to discuss their collaboration in real-time as they work.

Rocket Network has developed a custom Application Programmers Interface (API) that is integrated directly into third party audio products. This allows users to access the Rocket Network from within their favorite audio product. Rocket Network's Central Server system uses the API to provide a seamless data bridge between audio products, allowing multiple applications to be used on a single session at the same time.