Code licensing / software licensing [closed]

Question

I’ve been working on something outside of my day job and they have asked me if they can use it.

It is a closed source project, but I don’t mind giving them the source code; but I definitely want to retain the intellectual property and any improvements they make.

Is there a prewritten licence I could use for this?

Has anyone got any experience of this situation?

Update

I decided to drop the “any improvements they make” bit.

So I’m looking for a licence that has the following

• The intellectual property to stay with me

• they cannot sell the source code

• but free to use it in all products and to make modifications

I think if I modify the BSD license that will achieve this....

Copyright (c) 2011, (My Name) All rights reserved.

Use of source, redistribution and use in binary forms, with or without modification, are permitted provided that the following conditions are met:

• Source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

• The name may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

What you think?