This is a folder for small astronomical computation tools that I have written.
The Coordinates Tool page gets several hundred hits a month, suggesting that amateur astronomers and others are interested in coordinate-transform and other small tools.
If you have needs for other tools that you can't find elsewhere, feel free to send requests to me at firstname.lastname@example.org.
The Coordinate Tool will accept astronomical sky coordinates in several systems and epochs and calculate the values in all the other systems/epochs.
I created it because, while there are many web-sites that will convert between J2000.0 and B1950.0, or from arbitrary dates (e.g. http://nedwww.ipac.caltech.edu/forms/calculator.html) there are no decent web-sites that will convert to/from Galactic Coordinates, especially the "Old Galactic Coordinates" that were in use before 1959 and used, e.g., in the Sharpless-2 Catalog paper in ApJ.