The yt community is proud to announce the release of yt 3.0. yt (http://yt-project.org) is an open source, community-developed toolkit for analysis and visualization of volumetric data of all types, with a particular emphasis on astrophysical simulations and nuclear engineering simulations. This release of yt features an entirely rewritten infrastructure for data ingestion, indexing, and representation. While past versions of yt were focused on analysis and visualization of data structured as regular grids, this release features full support for particle (discrete point) data such as N-body and SPH data, irregular hexahedral mesh data, and data organized via octrees. This infrastructure will be extended in future versions for high-fidelity representation of unstructured mesh datasets. Highlighted changes in yt 3.0: * Units now permeate the code base, enabling self-consistent unit transformations of all arrays and quantities returned by yt. * Particle data is now supported using a lightweight octree. SPH data can be smoothed onto an adaptively-defined mesh using standard SPH smoothing * Support for octree AMR codes * Preliminary Support for non-Cartesian data, such as cylindrical, spherical, and geographical * Revamped analysis framework for halos and halo catalogs, including direct ingestion and analysis of halo catalogs of several different formats * Support for multi-fluid datasets and datasets containing multiple particle types * Flexible support for dynamically defining new particle types using filters on existing particle types or by combining different particle types. * Vastly improved support for loading generic grid, AMR, hexahedral mesh, and particle without hand-coding a frontend for a particular data format. * New frontends for ART, ARTIO, Boxlib, Chombo, FITS, GDF, Subfind, Rockstar, Pluto, RAMSES, SDF, Gadget, OWLS, PyNE, Tipsy, as well as rewritten frontends for Enzo, FLASH, Athena, and generic data. * First release to support installation of yt on Windows * Extended capabilities for construction of simulated observations, and new facilities for analyzing and visualizing FITS images and cube data * Many performance improvements This release is the first of several; while most functionality from the previous generation of yt has been updated to work with yt 3.0, it does not yet have feature parity in all respects. While the core of yt is stable, we suggest the support for analysis modules and volume rendering be viewed as a late-stage beta, with a series of additional releases (3.1, 3.2, etc) appearing over the course of the next year to improve support in these areas. For more information, including installation instructions, links to community resources, and information on contributing to yt’s development, please see the yt homepage at http://yt-project.org and the documentation for yt-3.0 at http://yt-project.org/docs/3.0 yt is the product of a large community of developers and users and we are extraordinarily grateful for and proud of their contributions. yt 3.0 features contributions from over 60 individuals, constituting almost 5000 commits. For many contributors, this is the first release featuring their work. Please forward this announcement on to any interested parties, and look for information soon about upcoming workshops focused on yt and applying it to your data. Thank you,