AstroInfo is licensed under the GPL v.2.
See the license.txt file.

NOTE FOR UPGRADERS TO VERSION 3.5 FROM VERSIONS BEFORE 3.5: Delete all the 
old catalogs from your PDA before installing 3.5 or later releases.

To install AstroInfo, you need to install a copy of the main program file,
Astro-xx_yy.prc (the one for your location) either on a memory card or in
RAM.

Then you need to install some databases.  All the "catalog" databases
can go on a memory card, either in the \PALM\Launcher folder, or in
\Palm\Programs\AstroInfo, but performance will be better if they go in
RAM (moreover, a significant amount of RAM is still used in connection
with these databases when AstroInfo is running--on low memory devices
you might get a reset if you have too many catalogs in the card).
A compromise might be to install the Tycho 7.6 catalog in RAM, and the
fainter Tycho catalogs on a card.

All databases other than catalogs must go in RAM (that includes constellation
lines and DST rules).

You will almost surely want to have a star catalog database.  If you have
very limited memory, you should install either
   BrightStarsMag5.pdb - Magnitude 5 subset of the Yale Bright Star Catalog
or
   BrightStars.pdb     - Yale Bright Star Catalog.

If you have more memory, you should consider instead installing one of the following
Tycho-2 catalogs
   Tycho5.0.pdb         - Tycho-2 up to magnitude 5
   Tycho7.5.pdb         - Tycho-2 up to magnitude 7.5
   Tycho8.5.pdb         - Tycho-2 up to magnitude 8.5
   Tycho10.0.pdb        - Tycho-2 up to magnitude 10
   Tycho11.0.pdb        - Tycho-2 up to magnitude 11
The Tycho-2 catalog is about 99% complete up to magnitude 11.

Additionally, you may consider installing:
   constellations.pdb  - Constellation lines, and constellation areas
                         (needed for go to constellation, and to draw
                         constellations)
   dstrules.pdb        - Daylight Savings Rules for different locations
   Bennett.pdb         - Bennett catalog
   Caldwell.pdb        - Caldwell catalog
   Collinder.pdb       - Collinder catalog of clusters
   Location.pdb        - List of locations, both for viewing in a PalmDOC
                         reader, and for choosing from in the AstroInfo
                         location options screen
   M31.pdb             - Catalog of objects in M31 up to magnitude 16.5,
                         from the M31 Hectospec catalog 
                         (http://www.cfa.harvard.edu/oir/eg/m31clusters/M31_Hectospec.html)
   Messier.pdb         - Messier catalog
   Herschel400.pdb     - Herschel 400 catalog
   rngc3.pdb           - Revised NGC 3 catalog by Steinicke
   ric3.pdb            - Revised IC 3 catalog by Steinicke
   saa100R2.pdb        - sci.astro.amateur catalog
   sac11.pdb           - Saguaro Astronomy Club Deep Sky 8.0 list, m < 11
   sac11-13.pdb        - Saguaro Astronomy Club Deep Sky 8.0 list, m < 13
   sac.pdb             - Full Saguaro Astronomy Club Deep Sky 8.0 list
   Planetsxxxx.pdb     - Planet/moon bitmaps for zoomed views, and for lunar
                         phase display.  You only need one of these (if you
                         install more than one, one will overwrite them all).  The
                         larger ones are higher resolution.
   RoadLinguaInterface.prc
                       - Install this if you want to look up additional object
                         information in a RoadLingua compatible dictionary.

If you have an ebook reader like eReader, you can install the following ebook
files:
   license.pdb         - GNU General Public License v. 2
   Astro.pdb           - instructions (may not be up to date)
   Location.pdb        - lat/long of various locations

If you would like to lookup objects in an external catalog in AbsoluteWord
RoadLingua, you will need to install RoadLingua.  Make sure you have an
external catalog installed for RoadLingua (see below for the only one I know of).
To look up an object, select it on screen in AstroInfo, and choose MENU | Sky |
Dictionary Lookup.  (Not all objects are supported, but all objects with Messier,
NGC or IC numbers should work.)

There is a free compatible NGC/IC catalog at http://tinyurl.com/9hg4vj ,
including annotated photos, for use with RoadLingua.  RoadLingua is normally
shareware, but it can be used without nags for free when launched from
external applications (this is something the Plucker project negotatied
with the RoadLingua developers), including AstroInfo.