I was wondering how you could create a map so that others can't edit it after they download it.
There are many ways.
Programs such as ProEdit, GUEdit, SCM Toolkit, StarForge, and others offer protection options. Just be sure to have a backup copy. You can also manually hex edit the map, but I can't really do that.
They are all avalible in our downloads database. I recommend you use Proedit, because:
- Using GUedit and SCMtoolkit is unprotectable
- Proedit 1.3 just came out today, lucky you found this website just in time

Remember that some also stop you from opening, so have that back up at all times, and keep old ones when you update maps, sometimes the updates make it worse!