Throughout my undergraduate career, I wrote many mathematical proofs which used many pages of paper.  Eventually I needed to buy a new laptop.  To save paper and help organize my work, I decided to buy a tablet PC and use it to write my work. 

I investigated the available software for writing notes on a tablet PC. The software was generally well done. However, every application was missing a major characteristic or feature that I needed. That is I needed an application that:

1. could be run on either Linux or Windows (and possibly Mac OS X)
2. save documents in a non-proprietary format
3. could be modified at the source code level
4. was open source (particularly licensed under the GNU GPL)

Microsoft Journal, although a good application, doesn't satisfy any of these conditions. Xournal and Gournal are very nice applications and are licensed under the GNU GPL. However, they can only be easily run on Linux. Jarnal is also a very nice application that can be run on Linux, Windows, and Mac OS X. However, it was written with a style of coding that made it hard for me to modify the code to meet my particular needs. If NoteLab doesn't meet your needs, I would suggest looking into these projects.

Having a mathematics and computer science bachelors degree as well as working on ISAW, an application used at Argonne National Lab to analyze neutron scattering data, I have become very adept to the java programming language.  As such, I decided to construct my own note taking application.  As such, construction of NoteLab began.