Your software should be open source as per the OSI definition
Your software should have a research application
You should be a major contributor to the software you are submitting
Should be a significant contribution to the available open source software that either enables some new research challenges to be addressed or makes addressing research challenges significantly better (e.g., faster, easier, simpler)
Should be feature complete (no half-baked solutions)
[x] Your software should be open source as per the OSI definition (#3)
[X] Your software should have a research application
[X] You should be a major contributor to the software you are submitting
[x] Should be a significant contribution to the available open source software that either enables some new research challenges to be addressed or makes addressing research challenges significantly better (e.g., faster, easier, simpler)
[x] Should be feature complete (no half-baked solutions)
From http://joss.theoj.org/about#author_guidelines