TITLE: How to distribute the source of programs used in a paper?
QUESTION [18 upvotes]: I have written a paper, which includes an appendix discussing how to obtain numerical evidence for the result of the paper. Now the computation essentially works as follows:

Create a large tridiagonal matrix.
Compute its eigenvalues.
Compute the difference of consecutive eigenvalues, and output it.

The implementation of such an algorithm is rather straightforward, but in order to look at large matrices, I started using algorithms from a package called LAPACK, which turned out to be faster then regular algorithms provided by Matlab. (I'm no specialist, so not exactly sure what happens).
I am curious if one should provide the source code for such a computation, and if yes in what form. I cam up with the following options:

Pseudocode (as  above)
Simplified matlab, that works with any installation of matlab, but is too slow to actually do the computations.
The real code, which most people will not be able to get to run without some effort.

I am also curious if one should include some sort of source code in the paper, and if yes, in what form? Or what people have done in such a case...
The simplified code is available at:
http://math.rice.edu/~hk7/ftp/matlab_code/SkewSpecDense.m
I have not put the real code online, because it requires external packages, and I am not sure how easy it is to install them...

REPLY [2 votes]: At least for numerical algorithms, submitting it and getting it accepted to ACM Transactions on Mathematical Software ensures that the code is mirrored on both the ACM site and the various mirrors of Netlib.

Added much later:
Nowadays, I would recommend setting up a GitHub or BitBucket account (or whatever is your preferred source management hosting site), put up your code there, and then include a link to it in your paper or preprint.