Thesis in use, potential employer wants to see source code EDIT: 

Let me clarify things and specify my concerns: 


I wrote a program for my thesis that solved a problem for the target establishment. 
The establishment now uses the program with my consent but nothing was signed and everything was verbal.
I applied for a job and that company now wants to see my program source code because it's relevant to the job I'm applying for.
My advisor is directly tied to the establishment using my program. I have notified him and we have scheduled to meet up and talk about it in a few days.


My concerns: ( just want to get more info before my talk with my advisor )


Is my program source code still my own? Have I accidentally given up my right to share it? Can my advisor and the establishment prevent me from sharing my source code to the company I'm applying for?
The source code is also included in the published thesis I submitted, doesn't that make it open source in a sense? Does that mean neither me or my advisor/establishment can claim ownership or anything of the code?
Are things different because my thesis is applied  to an actual situation as opposed to a theoretical situation? Like there is a period the thesis isn't made public (open source) like a grace period before it's open to the public?
This can be broken down into two issues:

(1) Can you show the new company your source code/can they ask to see it?

They have only asked to see it, not to use it. Maybe as a way to assess your skill, see if you fit their requirements etc. No problem in sharing this. You could even share a copy of your thesis. If they want to use the code, and say so, you can look into licensing options.

(2) Have you given away your right to share it?

No, because the absence of any written contract works both ways. It is part of your thesis, so it is still formally yours. Until and unless the target establishment tries to copyright it in some form, you have the right to share it.



An exception has been pointed out by David Z - there is a possibility that your advisor's 'tie-up' with the target establishment could constitute a work-for-hire agreement, and this may restrict your freedom to share. If such a case exists, either you or your advisor must be aware of the details and can find suitable redressal. If you were not made aware of this, ignore all concerns and share.



Do get your adviser's consent and guidance anyway, and also check your university policy on IP.