One such tool is Encitra. Similar to Google docs, numerous designers and stakeholders can participate online together in real time to design buildings, infrastructure, urban landscapes and more.
One opportunity to apply this tool and enter a competition is the Urban International Design Contest ("UIDC"). The UIDC facebook page is here: http://www.facebook.com/UIDC2017/.The contest is closed for 2017 but another competition is being planned for 2018.Here are some videos which demonstrate how this modeling tool works:
Light rail system in Uppsala, Sweden:
Podcar system in Uppsala, Sweden

