This program interpolates limb darkening coefficients from 
Walter Van Hamme's limb darkening tables. It is written in 
Java, so it runs on a variety of machines and operating systems.
I have tested it under Windows NT, Solaris 7, Linux, and OS/2.
Walter has kindly provided limb darkening tables for various 
metallicities.

*** Unix Users ***
If you want to run it on a Unix machine that has the Java runtime
environment (JRE) already installed (newer Sparcs will; you can test it
by typing jre at a prompt and see if anything happens; if needed, you can
get the appropriate JRE from the Sun web site but your sysadmin
will probably have to install it.), you should grab ld.tar.gz and put
it in a directory (e.g., I put it in /home/terrell/LD). Then unpack it:
gzip -d ld.tar.gz
tar -xvf ld.tar
(or if you have gtar, just "gtar -xvzf ld.tar.gz" will do it all)
Then to run it, edit the ld.csh file and change the /home/terrell/LD
paths to wherever you put the file on your machine. When you close the
graphical window, you'll have to hit Ctrl-C in the shell window to end
it.

*** Windows Users ***
If you want to run it on a Windows machine, grab ld.zip and unzip it (I
have a command line unzip.exe on the site that you can use- unzip
ld.zip will do the trick). If you don't have the JRE installed on the
Windows machine, grab 
jre1_1_8-win.exe
and run it. It has an installation program and you can just accept the
defaults. Once the JRE is installed, unzip the ld.zip file in a
directory (on my NT machine it was e:\binary\ld\new). Edit the ld.bat
file and change the E:\binary\ld\new paths to the path where you put
the ld.zip file. Then from a command prompt just type ld and hit
return. That should start it up. You'll see a shell window pop up
immediately and, after a second or two, the graphical window. Hit
Ctrl-C in the shell window to close the program when you are done.

*** Running the program ***

Once you have the program running, enter valid T and log g values, then
hit the Interpolate button. The first time through on a given
metallicity, there will be a pause of a few seconds as it reads in
Walter's tables. Subsequent interpolations will go much faster since it
doesn't have to read in the tables. To change the metallicity, just
select the one you want from the dropdown box on the left. If you enter
a (T, log g) set and have nothing happen when you hit the button, it
probably means that you are outside the tables. (That is one of the
things I still have to add- a message saying that the values are
invalid, as well as an indicator of some sort when it is reading in the
tables.) So, there are a few cosmetic things still to do, but my
testing of the interpolation indicated that all was well
where it counts. I did a variety of interpolations by hand and the
program results matched up with them. As in the old program, I'm just
doing a bilinear interpolation.

Dirk Terrell
Southwest Research Institute
terrell@boulder.swri.edu

References:
Van Hamme, W. 1993, Ap. J. 106, 2096
Available online at
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1993AJ....106.2096V&db_key=AST&high=37f28a9cf319690