Bitbucket is an Australian competitor to Github in source code versioning and hosting. Bitbucket exists since 2008 and has been supporting GIT since 2011. Bitbucket has a free-tier which allows small companies to host unlimited number of private respositories.
Bitbucket's owner Atlassian produces many other related tools for software developers. One of their most famous products, task and project management system JIRA, was released in 2002. Other services include Bamboo (continous integration), HipChat (intra-company chat), Confluence (collaboration and documenet management).
Atlassian has more than 1000 employees. Their main office is in Sydney, Australia.