We are developing ROOT according to the principle of:

Release early and release often

However, since a very large portion of the user base requires a stable product we generally keep three version of the system available for download. The dev, pro and old versions.

The dev version evolves quickly, with monthly releases. Use this to get access to the latest and greatest, but as a side effect there might be some instabilities. However, by trying out the dev version you can help us converge much more quickly to a stable version that can then become the new pro version. If you are a new user we would advice you to try directly the dev version.

The RC version is a Release Candidate of the next pro release. We typically have two RC's (one month and two weeks) prior to a pro release. The idea of the RC is to only contain bug fixes and to provide a stable test platform for users to ready their code for the new pro release.

The pro (production) version is a version we feel comfortable with to exposing to a large audience for serious work. The change rate of this version is much lower than for the dev version. In the order of 6 months.

The old version is the previous pro version that people might need for some time before switching to the newpro version. The old change rate is the same as for pro.

For each of the three version we provide the full source and pre-compiled binaries for most of the supported platforms (although for the dev version we can not always keep up with providing all the binaries).

The following versions are available for download:

After downloading and unpacking please read the included README/README file on how to set the necessary environment variables.