Skip to the navigation links
Last modified: 26 July 2019


System Requirements

CIAO is supported on a number of operating systems, which are listed on the Platform Support page. Certain system requirements are necessary to successfully install and run CIAO.

Installation requirements

The suggested route for CIAO installation is by the ciao-install script, available from the download page. This script requires bash to run it, and either curl or wget to download the binary packages. The gzip tool is required to uncompress the binary packages, and tar to unpack them.

Memory and Disk Space

Chandra data files are large, which implies that certain processing and analysis operations will work more efficiently when they have access to large amounts of RAM. We recommend a minimum of 1Gb main memory. A full CIAO installation, including the background calibration files will require ~15Gb of disk space. The disk space for individual observations varies from a few megabyte to several gigabytes depending on the target as well as the exposure time and instrument configuration.


Pre-built binaries for CIAO 4.11 are created using CentOS 6.9 and Ubuntu 14.04 machines. These are expected to be compatible with most recent distributions, but may not work with old versions.


X11, the X window system.


ChIPS requires OpenGL, an interface for system graphics. OpenGL is part of the xlibs development package.

Apple OSX/macOS

Pre-built binaries for CIAO 4.11 are only available for OSX 10.11 (El Capitan), macOS 10.12 (Sierra), and macOS 10.13 (High Sierra). Users with macOS 10.14 (Mojave) should use the High Sierra build.


X11 was included as an optional package in earlier versions of OSX; however, it currently must be installed separately from the XQuartz website. Users must be using XQuartz version 2.7.11 or newer.


CIAO requires users have the Apple's Xcode tools installed on OSX/macOS. These tools are needed during the installation process to configure the programs to run on users machine.

Additionally, ChIPS requires OpenGL, an interface for system graphics. OpenGL is included in Xcode.

X11 System Libraries

CIAO requires several X11 related system libraries to be installed. These are usually already installed on most end-user Linux machines; however, they are frequently omitted when running on "headless" clusters and Apple users need to install XQuartz separately.

Users are responsible for installing them via the package manager (e.g. yum, fink).

The names may differ slightly but here are the known packages:

Doing an ldd on our executables and libraries will produce a list something like the following list of system libaries that will either be located in /lib or /usr/lib.