We are proud to announce the public release of Enzo version 2.2. This intermediate release contains a few new physics modules, reorganized and updated documentation, revamped answer testing, improvements to code infrastructure, as well as numerous bug fixes. In a little bit more detail:

1. New physics capabilities — (a) Thermal and chemical feedback from Type Ia supernovae, with mass loss and luminosity fits provided by K. Nagamine; (b) H₂-regulated star formation, in which the star formation rate is proportional to the density of molecular hydrogen (determined from Krumholz, McKee, & Tumlinson 2009), rather than total gas density.
2. Upgrades to the Enzo Answer Testing Framework — Includes both functional improvements and vastly improved documentation. The results of two test suites ("quick" and "push") have been uploaded to an Amazon Cloud instance, allowing users to compare to an Enzo Community "gold standard". Alternatively, answer testing can also be done by comparing to locally generated results.
3. Improved Documentation — (a) Descriptions of 175 previously undocumented parameters; (b) Parameters have been broken up into groups; (c) Brief explanations of the functionality provided by (most) Enzo source files; (d) Description of the new Enzo performance timers; (e) Examples of how to debug Enzo.
4. Code infrastructure improvement — All fortran routines have been modified to explicitly specify the type at compile time, eliminating the need for compiler flags to ensure 64-bit precision.
5. Timing and performance measurement and plotting tools — Support for simple, lightweight measurements for the timing and performance of Enzo. This allows one to examine which functions are using the majority of the simulation runtime, and how this varies across multiple processors.

With this release we continue our efforts to consolidate The Enzo Project's web presence, with the goal of lowering the barrier to entry for new users and easing further code development:

• Enzo's main webpage continues to be http://enzo-project.org. Links and information can be found here for both developers and general users.
• Both stable and development versions of the Enzo code are now hosted on Bitbucket.
• For news and updates please follow our google+ page: The Enzo Project

Enzo 2.1.1

Release Date – Oct. 27, 2011

A minor release featuring mostly bugfixes. See the changelog for details.

Enzo 2.1.0

Release Date – Oct. 17, 2011

We are proud to announce the public release of Enzo version 2.1. New with this release is an extensive answer testing facility, additional physics capabilities, and AMR performance enhancements. New physics capabilities include isotropic and anisotropic heat conduction, X-ray ionization/heating, massive black hole particles, 4th-order accurate gravity solver, distributed stellar feedback, shock tracking, and improved molecular hydrogen chemistry. Performance improvements include Hilbert curve dynamic load balancing, faster ray tracing, and ray merging. We have improved Enzo’s inline analysis using the yt project, as well as user documentation for the entire Enzo codebase. We have also simplified the generation of multi-mesh cosmological initial conditions.

In addition to code upgrades, we have upgraded and reorganized our online repositories and documentation. The Enzo Project’s main website is now http://enzo-project.org/ . Links and information can be found here for both developers and general users. Our stable releases will continue to live on our Google code website: http://code.google.com/p/enzo/ . Users can clone a mercurial repository of our stable release code or download a tarball of the code (http://code.google.com/p/enzo/downloads/list A simple quick-start guide can also be found here: http://code.google.com/p/enzo/wiki/EnzoBootCamp We will now support versioned documentation for all stable releases since Enzo 2.0 in addition to the development code on enzo-project.org. The documentation for Enzo 2.1 is located here: http://enzo-project.org/docs/2.1/.

Development will now move to our new Bitbucket repository where all users are encouraged to make contributions to the code by forking the main repository, located at https://bitbucket.org/enzo/enzo-dev . An explanation of new developer guidelines can be found here: http://enzo-project.org/docs/2.1/developer_guide/index.html. The current release of Enzo 2.1 features contributions, bug fixes and enhancements from an additional ten individuals (over the course of 2700 changesets) since Enzo 2.0, and through our new development infrastructure we are expanding our ability to solicit and review contributions.

• Main website: http://enzo-project.org/
• Mailing List: https://groups.google.com/forum/#!forum/enzo-users
• Stable repository: http://code.google.com/p/enzo/
• Tarball of Enzo 2.1.0: http://code.google.com/p/enzo/downloads/list
• Enzo Boot Camp (a quick-start guide): http://code.google.com/p/enzo/wiki/EnzoBootCamp
• Enzo 2.1.0 documentation: http://enzo-project.org/docs/2.1/
• Developer’s repository: https://bitbucket.org/enzo/enzo-dev/overview
• Developer’s guidlines: http://enzo-project.org/docs/2.1/developer_guide/index.html

Enzo development is supported by grants AST-0808184 and OCI-0832662 from the National Science Foundation.

Release Date – Jul. 1, 2010

We are proud to announce the public release of Enzo version 2.0. Enzo is a parallel code for astrophysical and cosmological simulations utilizing adaptive mesh refinement. Enzo 2.0 features many new physics capabilities including ideal MHD, radiation transport (ray tracing and flux limited diffusion), star particle class, metallicity-dependent cooling, and several new hydro solvers. More importantly, we have introduced new software tools to make using and developing Enzo easier. We have adopted distributed version control using Mercurial which supports the growing Enzo developer community. The documentation has been made more accessible and is now distributed with the source code. We have more than doubled the number of test problems and example problems as well as the number of developers!) In addition, we have added solution testing to the nightly regression tests.

Enzo 2.0 is the product of developments made at UC San Diego, Stanford, Princeton, Columbia, MSU, CU Boulder, CITA, McMaster, SMU, and UC Berkeley.

Enzo 2.0 now lives at http://enzo.googlecode.com/ to reflect its multi-institutional provenance. Prospective users are also encouraged to view online lectures from the 2010 Enzo Users' Workshop at http://lca.ucsd.edu/workshops/enzo2010.

Enzo development is supported by grants AST-0808184 and OCI-0832662 from the National Science Foundation.