Most software/libraries that I want to make are already made by others. Similarly, there is a lot of tools in natural language process area. There are free and maintained and have been used by a number of people. It is worth to take a look and explore some of them. Here I list some tools that may be useful for natural language process research area.
1. lingPipe
2. Lucene
3. SharpNLP< 4. OpenNLP