Dear EM-ers, Please be advised that a beta-version of RELION-2.0 is now downloadable from the wiki at http://www2.mrc-lmb.cam.ac.uk/relion As we've moved from our old tarball system to an open git repository on bitbucket, the line between a beta and stable release has become more diffuse. Still, after a few months of beta-testing by a group of experts, we think RELION-2.0 is now ready for a more general round of beta-testing. The main new things compared to the previous stable (1.4) release are: 1) GPU-acceleration of 2D/3D classification and 3D auto-refinement. This has been done through a wonderful collaboration with the group of Erik Lindahl at the SciLife lab in Stockholm, in particular by his students Dari Kimanius and Bjorn Forsberg. This makes it possible to do cryo-EM structure determination in a matter of days on inexpensive desktop machines (as opposed to weeks on expensive clusters before). The paper describing this is not yet out, but we have an older version of it on BioRxiv: http://biorxiv.org/content/early/2016/06/19/059717. 2) Processing of helical assemblies. This is work done by my student Shaoda He. We're writing up the paper right now, and meanwhile there is info on how to use it on the wiki. The first structures to have been solved with this method are on their way too. 3) A pipelined-approach to image processing (including a new GUI). RELION-2 will keep track of all your jobs, thus facilitating book-keeping and workflow-based automation (for example on-the-fly processing during data acquisition). Again, a preprint of the corresponding paper is on BioRxiv: http://biorxiv.org/content/early/2016/09/29/078352 NVIDIA has kindly sent us a Titan-X GPU to be given away to the person/group giving the most useful feedback during beta-testing. Please use the bitbucket issue-reporting functionality to tell us about bugs: https://bitbucket.org/scheres/relion-devel-lmb/issues. Please continue to use the ccpem email list (and not direct emails) for user questions: http://www.jiscmail.ac.uk/CCPEM. Have fun, Sjors, Erik, Dari, Bjorn & Shaoda -- Sjors Scheres MRC Laboratory of Molecular Biology Francis Crick Avenue, Cambridge Biomedical Campus Cambridge CB2 0QH, U.K. tel: +44 (0)1223 267061 http://www2.mrc-lmb.cam.ac.uk/groups/scheres