Internet Doom Explorer - non-portable win32 closed-source (yet) launcher for client/server Doom ports :) - support Odamex now.
Get it here
For something which has little purpose other then making end users happy, open source would definitely be my choice. The reason being is that the main developer can worry abou developing their program as opposed to making sure it works on every OS, and people with specific interests can add whatever they need to it, keeping the whole community happy (being linux compatibility, or other modifications). There is no way I can force you to release the source, but it is my recommendation.
Also, if you die, having the source available on the internet allows the project to be continued ^_^.
* Zorro knocks on wood...