Vert.x was started in June 2011 by Tim Fox in his spare time while he was working at VMware. The inspiration for the project came from two main areas:
The growing interest in non blocking, asynchronous approaches to application design motivated by scalability.
The recent trend towards stripped down simplicity in APIs and a rejection of complexity that had dominated application platforms in the previous 10 or more years.
In particular the project was influenced by Node.js which was getting a lot of attention at the time. There was nothing similar for the JVM and the idea was formed to create a project superficially similar to Node.js but running on the JVM, and which could leverage the superior virtual machine. Since the JVM also supported multiple languages (unlike V8) the idea was the user could choose from multiple languages in which to code their application.
Initially the project was named 'Node.x' - the 'x' representing the fact that the platform was polyglot, but Fox pre-emptively renamed it a few months later in order to avoid any potential future trademark issues with Joyent who own the Node.js trademark. The new name chosen was Vert.x (pronounced 'Vertex') - again the .x representing the polyglot nature of the project, and a vertex is of course a synonym for a node.
The latest release of Vert.x is 1.3.1, and there is a healthy and growing community. Vert.x has attracted a lot of attention so far and is currently one of the most followed Java projects on github
Work has already started on Vert.x 2.0 which aims to improve the platform in multiple areas and take the project to the next level.