Software license without modify

Question

I have my own company, and I would like to release our customer management system as open source so everybody can see what we do.

But it is very important to me that I don't want anyone else to use or modify the software.

My idea is to modify the MIT license, because it is simple to understand.
But I am not sure about modifying a license as I'm not a lawyer.

Is there a license that fits my needs? Specifically, I want people to be able to see our system but not be able to use or modify it.

Answer 1

First of all, what you plan does not satisfy the OSI definition of Open Source. Some people are quite touchy about that, so I recommend not using the label Open Source anywhere.

Unfortunately I don't know any accepted term for licenses that make the source code available but are too restrictive to be considered Open Source. Microsoft calls this their Shared Source program, but I haven't seen that term in other contexts.

I wouldn't start with a permissive license like MIT, since the spirit of what you want to achieve is pretty far from MIT.

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The Microsoft Reference Source License looks pretty similar to what you want.

The relevant clauses are:

"Reference use" means use of the software within your company as a reference, in read only form, for the sole purposes of debugging your products, maintaining your products, or enhancing the interoperability of your products with the software, and specifically excludes the right to distribute the software outside of your company.

Copyright Grant- Subject to the terms of this license, the Licensor grants you a non-transferable, non-exclusive, worldwide, royalty-free copyright license to reproduce the software for reference use.

I'm not sure if the license itself is protected by copyright, so you might not be able to simply use it.

Answer 2

Since the purpose of this license you seek is to assure your customers that your software is doing what you say it does, you don't really need to put your source code out as open source.

It doesn't take a genius to fork your code then rebrand it(even if you say in the license they're not supposed to do that, and trust me, its hard to litigate against foreign entities) so going open source might actually come back to bite you.

What you could do in my opinion though, is to have your source code audited, by a third party or by a group selected by your customers(just be sure to put the auditors under NDA so they don't spill the source code or they can be held legally liable for it), so that they can be assured that your code does what its supposed to do. Besides, you can even put this out as an extra bonus for your sales pitch. "We have our source code thoroughly audited by third parties at least once a year to assure you, our customers, that we are doing our best to take care of your data"

something like that.