We are trying to have our own startup, with a middleware application to glue small applications with enterprise legacy systems.
for such middle-ware to function properly, we will need some sort of messaging system to make different components talk to each other in a reliable way. the alternatives are:

• use an existing messaging system, such as 0MQ, jBOSS, WebSphere MQ, etc.
• build our own messaging system the way we see the problem

I am more biased towards the later option for the following reasons:

• to have more control over our final product
• to avoid any licensing problems later on
• to learn about messaging while writing the code
• to invent something new, that might cost us lots of $$$ if reused an existing system

What would you do if in my shoes?