kpallenh:  Consider looking at Deki Wiki, an Open Source wiki by MindTouch.  Below I've addressed all of your requirements. 

1. Free

Yes.  There are options for commercial support plans.

2. Free

Yep.  We also have support plans available.

3. Did I mention Free?

Sure is...did I mention we have support plans

4. Datastorage in local Files, not a hosted database

Deki Wiki stores all information in a MySQL database that will be located on your local machine

5. Support WYSIWYG either default or by plugin

By default you have a WYSIWYG editor

6. Good ability to change the look either by templates or some other way. Support treeview hierarchy.

Deki Wiki has a tree hierarchy by default along with the flexibility to override CSS styles within the control panel

7. I want to be able to allow a page to be edited but perhaps with a password.

Deki Wiki has granular permissions that can be applied as big as the whole wiki and as low as a single page. 

8. Older versions of a page must be available so no data is lost.

Deki Wiki versions all of changes to the pages and saves them for a full audit trail.

9. Good full text search

Deki Wiki uses Lucene, an enterprise search engine developed by the apache foundation that not only searched the text but also the contents of attached documents like MS office and PDFs.

10. Easy to insert and edit images.

Deki Wiki has a popup dialog within the editor to insert and edit the image

11. If it has a map-function that allows users to set a point on the map with a link to a wiki-page it is a bonus.

Deki Wiki has integration with google maps that allows you to map a point on the google map and embed it on a wiki page

12. I am open to learning a new language but am looking for the minimal learning curve.

What you are looking at doing can be done without knowing a programming language.  This is how powerful Deki Wiki is.



If you have any other questions about Deki Wiki please feel free to contact us here: http://wiki.mindtouch.com/support

Karen,

  We have a very robust community of users on our community site which can help you with your Deki Wiki.  I always encourage people to get support as it is good to have it for reference, support, and good for upgrades etc.  You can do it though with our VMware certified appliance which makes it easier to deploy and manage.  You can download the software here: http://wiki.mindtouch.com/Deki_Wiki

What are you interested about in regards to MySQL?


Pronunciation is deckeee wiki.

Karen,

   I'd recommend taking a look at the documentation at http://www.mysql.org or there are also some handy tutorials online such as this: http://w3schools.com/php/php_mysql_intro.asp

Otherwise I'd search on Google for an intro to MySQL. 

Hope this helps.