FITS I/O software written in IDL is available as part of the IDL
Astronomy User's Library, a central repository for general purpose
astronomy procedures written in IDL, including procedures to convert
between spherical coordinates and plane map coordinates. The library is
not meant to be an integrated package but rather is a collection of
procedures from which users can pick and choose for their own use.
Submitted procedures are given a cursory testing but are basically
stored in the library as submitted. The Astronomy User's Library is
supported under the NASA Astrophysics Software Aids program. The
material is available through
http://idlastro.gsfc.nasa.gov/homepage.html or at
ftp://idlastro.gsfc.nasa.gov (IP 220.127.116.11).
The Astronomical Data Center (ADC) at NASA/GSFC has developed a FITS Table Browser, which has been tailored specifically for use with the ADC CD-ROMs but may be used with other FITS ASCII tables. It reads standard FITS ASCII tables and allows the user to browse through them interactively and selectively display any field or record in a table. File extraction facilities permit writing all or part of the input table to disk in FITS or text file format. It is available at ftp://adc.gsfc.nasa.gov/pub/adc/software/browsers/ftb. See the file ftb_user_guide.txt for instructions on downloading, installation, and use.
The IUEDAC software (which is written in IDL) includes a FITS reader that can read primary HDUs and image extensions, ASCII tables, and binary tables, including binary tables with variable-length and multi-dimensional arrays. The accompanying FITS writer can write primary HDUs, image extensions, and binary tables including multi-dimensional but not variable length arrays, but it cannot write ASCII tables. The software is available from http://archive.stsci.edu/iue/iuedac.html, or ftp://archive.stsci.edu/pub/iue/software/iuedac. and runs on Unix, Ultrix, VMS, MacOS, and Windows systems.
The National Center for Supercomputing Applications (NCSA) Hierarchical Data Format (HDF) group is developing a FITS server-side browser. Among the things it can do now are the following:
NCSA is also developing FITS-HDF conversion utilities. Because this site is evolving rapidly, the individual URLs have been changing, but it should be possible to find the FITS material by starting at http://hdf.ncsa.uiuc.edu/.
The three principal astronomical image processing software packages-- AIPS, the ESO-Munich Interactive Data Analysis System (ESO-MIDAS), and IRAF--incorporate substantial support for FITS.
New software to display FITS images continues to be developed. Some nonproprietary packages are mentioned in one section of the FITS Basics and Information. A general discussion of software to convert between formats, including FITS, is in part 2 of the Graphics File Format FAQ, which is periodically posted to the newsgroups comp.graphics.misc, comp.answers and news.answers. It is also archived at ftp://rtfm.mit.edu/pub/usenet/ and http://www.cis.ohio-state.edu/hypertext/faq/usenet-faqs/. The MIT site is often busy. The Ohio State site is occasionally reorganized with changes in the lower level of the URL.