‘Alternativa3D’ is developed by a Russian company which is working on this platform for more then 10 years(as they claim ), and cooperating close with Adobe and working in pre-release groups, and participate in developing of new Flash Player versions.
‘Alternativa3D’, which is intended for displaying 3D graphics in the Flash Player environment. You can use this technology in wider areas such as 3D websites to multiplayer browser games and applications for social networks in full 3D.
Alternativa3D version 7 has been widely used in the architectural and building sector, interior design and internet advertising. They are also providing servers for online gaming. AlternativaCore is a cluster of several Linux-powered Java servers. It is a ready to use core for creating real-time and turn-based multiplayer online games. This client-server solution helps in version control, high speed data transfer, load balancing  system, store unlimited amount of data, faster and easier development of games, allows expansion, decreases expenses, support payment systems, social networks support etc. For more details just visit: http://alternativaplatform.com/en/alternativa3d/
The best thing is that Alternativa3D is free of cost, so just download it and explore the possibilities. But one thing to remember, you need to have a good understanding of Actionscript 3 and Flash.
Actually Adobe Flash team is working on technologies which make possible to create and play 3D games through Adobe Flash Player. Adobe team is working on a new set of 3D GPU accelerated APIs that delivers advanced 3D rendering in Flash Player and AIR. This API codename is ‘Molehill’. For more information just visit this link: http://tv.adobe.com/watch/adc-presents/molehill-3d-apis/