CASA 6.5 is based on Python 3, and available either as a downloadable tar-file distribution with Python environment included, or as a modular version that can be installed with pip-wheels.
Manual processing can be done with any CASA version, but ALMA and VLA pipelines may differ and are not always included, so download the correct CASA version for pipeline use.
CASA: the CASA versions listed above are built on specific versions of Linux RedHat and Mac OS, they are expected to work for mutiple LINUX and Mac computer operating systems, including Mac OS 12 and certain Ubuntu versions. In CASA Docs we list a compatibility matrix, which shows the different Operating Systems and Python versions on which current and future CASA versions are expected to work, and for which the CASA team accepts bug reports.
However, note that CASA is only fully validated against the operational configuration of NRAO instruments (currently RHEL7/Python 3.6).
CASA 6 can optionally be installed through modular pip-wheels, with the flexibility to build CASA tools and tasks into a customized Python environment. Instructions on how to install the pip-wheel version of CASA 6 can be found in CASA Docs: CASA 6 Installation
The modular pip-wheel version is not yet used in production by ALMA and VLA, and does not include any pipelines.
For the use of pipelines and recommended CASA+Pipeline versions, please consult the ALMA pipeline and VLA pipeline webpages.
Release information for previous casa versions can be found in (for CASA 6.2+), or in the archival version of archival version of CASA Docs (CASA 5.0 - 6.1).
Pre-release versions of CASA can be found here (see also this download through Google Drive). Pre-release versions reflect ongoing CASA development and are not supported. Use at your own discretion.
CASA 6.5 is fully validated against the operational configuration of NRAO instruments. Furthermore, automated verification tests and manual package testing have been performed for the following operating systems:
Linux RedHat 7
Mac OS 12 (Monterey, x86 Intel)
Other systems on which we expect CASA to work, including certain versions of Ubuntu, are listed in the compatibility matrix on CASA Docs. CASA accepts bug reports for all combinations of OS and Python that are listed there.
Mac M1: CASA for Mac OS is officially supported for x86 Intel chips. At this moment, the CASA team does not have the resources or infrastructure in place to produce, test, and support CASA packages for machines with the ARM-based M1 chips. Nevertheless, automated testing shows that CASA tasks and tools work on M1 machines. We therefore recommend that users with M1 machines should use the OS 12 x86 packages or pip-wheels to run CASA in those machines, and report any problem to casa-feedback@nrao.edu.
Other LINUX: CASA may also work on other flavors of Linux, but this is at the discretion of users. Some tips from the community can be found here.
NRAO has installed a suite of CASA and pipeline versions for local users, visitors, and users who request remote access to NRAO machines. More information on running CASA locally at NRAO can be found here.
To efficiently run CASA, a balanced hardware configuration regarding memory, processing
power and file I/O may be required. Recommendations on the CASA hardware requirements for VLA and
ALMA data can be found on this 'Hardware Requirements' page.
DISCLAIMER: CASA now collects usage statistics including task execution timings
and crash reports. This data will be periodically sent back to NRAO to
guide future priorities and decision making. All collection is anonymous and contains no scientific or personal data. For more information, or instructions on how to disable telemetry recording, see CASA Docs
Linux
Mac
The above CASA versions can also be downloaded from our 
(for CASA 6.2+), or in the archival version of archival version of CASA Docs (CASA 5.0 - 6.1).
