These instructions only apply to versions 0.6.10 and older. Starting with carto version 0.7.0 use the new installation instructions.
Install Java using the instructions from Sun. The Java version number must be at least 1.2. Carto will not work with older versions. Version 1.3 is recomended.
Unpack the .zip this will produce a directory named "carto".
If you do not know how to unpack zip files, the procedure for unpacking them depends on what kind of computer you have. On PCs the most common programs for doing this is pkunzip and winzip.
Get a shell prompt (for windows this is a DOS window).
Go to the carto directory.
Go to that directory and type
java -Xmx64m Carto
(The capital letter is important even in windows) In place of the number 64 you can use the amount of actual memory installed on your computer.
The most common problem is for Java not to be instaled correctly. Make sure your PATH includes the java "bin" directory. Note that Carto requires Java2 (Version 1.2) or higher. Also note that Java2 is version 1.2 (but version 1.3 is not Java3).