>I've been developping an application over the last year for a vertical market. I'm not done with it yet but at this stage it's already used by some companies.
>
>Now here's the catch. A big company that has already develop solutions for that same vertical market is going to develop an application very similar to the one I've been working on.
>
>Now how much should I panic here? Keep in mind that I'm a one man band and that this competitor company has a lot more resources than I.
>
>What should be my next move? Approach that competitor to show them what I did so far hoping that they will make me an interesting offer. Offer that could be to get me to join them or get me to sell them what I did? Should I offer them my services because of all the things that I know so far about that solution?
>
>Do you have suggestions on things to do so I won't be left with nothing in the long run? Is there a site that could give me more help on that? Is there a book that I could get?

I was in a similar position several years ago. I had developed software for a medical billing company and I had it copyrighted. They decided they were going to sell it to another company some time later and I told them that would be fine after they paid me. I negotiated a nice tidy sum from them before giving it to them. Of course they went bankrupt within a year, but I got out with my money and eventually retained the software. Get a copyright, then go see them.