Today we are announcing the first step in that end-of-life process, the deprecation of the Web Player. When Unity marks a feature as deprecated it means that the use of the feature is no longer recommended and that the feature will be removed in a future release. For the Web Player, Unity 5.2 and 5.3 will still be able to publish Web Player content, but Unity 5.4 (to be released in March 2016) will no longer ship with Web Player support. The Web Player will then become an unsupported product.
So, what does this mean if you want to target the web with Unity from March 2016 onwards? With 5.4, the only option to generate web content in Unity is our WebGL export, which is currently in preview. Unlike the Web Player, WebGL is not a plugin, but uses standard APIs exposed by the browser. This means that WebGL content runs without requiring any plugin install. However, it is important to understand that WebGL is a different platform from the Web Player and does not match the feature set or performance of the Web Player. We are working closely with browser vendors to make sure this gap becomes as narrow as possible, but there are some limitations which are defined by the platform - such as restrictions on the networking protocols you can use, which are mandated by security concerns.
Learn more about WebGL support in Unity in our documentation.
So, what about all the existing Web Player content that exists on the web, can users still play my Unity Web Player powered games?
The short answer is yes, all Web Player content will still be playable in browsers that support NPAPI plugins. Unity will still allow downloading of the Unity 5.3 Web Player to run any existing content. Note that it will be necessary to use either a browser which still supports NPAPI or on older version of a browser released before NPAPI support was dropped. Additionally, Web Player builds will no longer be maintained so it will be necessary for us to make end users aware of the potential security risks. Unity deeply understands the importance and historical relevance of Web Player powered games and keeping this back catalogue of games playable is something we care about. We have formed a working group to investigate alternative technical solutions and will update the community as we progress.