OpenJUMP

OpenJUMP is a Geographic Information System (GIS) based on Java.
This great GIS tool uses Geographic Markup Language (GML), Web Map Service (WMS), and Web Feature Service (WFS) standards.

It offers drawing and editing tools to draw almost any kind of geometric form. You can add attributes to any geometric form. It also allows querying on its attributes: area, length, number of points, etc.
It allows adding layers as you need. You can show all the layers at the same time or just the layers you are working on. It also provides a tool to perform analysis on the geometric of the objects. This GIS tool allows you to open Data Store Layer and WMS layers and show them. Also it allows saving views as Raster or Scalable Vector Graphics (SVG) formats. It includes and API to integrate information.
Some of the new features of this release are: the I18N support, advanced query features, a fence function that allows to zoom only the area of the fence, etc.
The installation process is very easy to perform and it requires Java 1.5 or later. The documentation is not bundled with the program but there is a great documentation on its website including its wiki section.
OpenJUMP runs on Windows, Mac OS and Linux platforms. It will work in any platform that runs Java 1.5 or later.