This is Day 4 of 30 (in 30 days of Geek)…
What is the greatest application written to date?
This is a tough one. So many choices.
One project I have been working on for the last couple years is a common Java application framework, allowing multiple pages wrapped by an application layer which handles the UI elements such as the toolbar, statusbar, buttonbar etc, and has a page navigation tree on the left. Each page is then displayed in the main area, inside a JXLayer pane. The application framework has customised logging built in, a set of database tools allowing both embedded Derby DB and networked MYSQL access and DB tools such as importing and exporting databases, and has a built in thread manager to deal with spawned multi-threaded business logic. Additionally, it has integrated java help, Google Earth KML exporting, serialio USB Serial communication, and lots of utility stuff that comes in handy.
I am using this framework for multiple applications, including the one I am working on right now, which is tied heavily to our customised satellite tracking collars. It allows users to configure hardware used in wildlife tracking, allowing users to set up and deploy loggers and satellite transmitters, and deals with downloading near real-time data for GIS analysis etc.
The application (that I am working on a new version for right now) downloads data from fastloc transmitters, 
which are tiny devices that capture a super fast snapshot of what satellites are visible in the sky, and then transmits this data via Argos satellites. The software downloads this data, and uses satellite RINEX data and custom C libraries to triangulate where the transmitter was when the snapshot was taken. It allows tiny sized logger packages, but still gives GPS accuracy. Out software then decodes this data and allows users to view it in Google Earth or export for subsequent analysis.
Definitely cool technology.
