The software is called the Roll20 Virtual Tabletop, and was a very popular kickstarter project. From what I have experienced in the short time I have fiddled with it, it is a VERY powerful tool...
I have heard nothing but great things about this software so far. Why? Cause as I have been quickly finding out, with the likes of RPTools the system often requires a touch of knowledge on the mechanical side of things, making it relatively un-intuitive and very intimidating for newer players.
The Roll20 VTT is something that is very new, utilizes some of the fun elements that already come packaged with Google hangouts, tossed in with a very user friendly interface that doesn't invade on a lot of what would be considered the gaming tabletop.
Additionally, there are a LOT of resources available to the players themselves: Ranging from quick searches for player tokens, easily modified character statistics, and enough options to make even the most devoted Role Play Gamer happy.
Through my experiences, it is still very much a product in development. Features such as the ambient jukebox, attack sounds, and various formatting options currently do not work with Firefox or Google Chrome, though despite that the product is very much functional, and has a LOT of potential (including modules that people can potentially put together and share with the community on the fly).
Additionally, it provides one central point for all settings for voice, tabletop, character sheets, and playing aids. It does a GREAT job of keeping it very simple to use, and the fact that all one needs to do is share the link and they are good to go really takes it to a whole new level. This is some good design, and I look forward to see what they have to share next!
If you haven't already, feel free to check out the linked website above, as well as the YouTube Videos found here:
Hopefully before the end of the week I can provide something more substantial, though I had to share this as it was most certainly something to keep an eye out for!