Can it do advanced searches?
It can do sophisticated searches. And if you wanted to create pages with lots of buttons, those searches can be made more complex. Here's a URL for a keyword search for "camp", limited to those items tagged "interior" from 1921:
But getting there was a matter of clicking the facets. You could create one, but by default there's no complex search screens into which users enter the details of their search.
How long does the search function take to implement? Can it be customized?
Scriblio can be installed in about ten minutes. There's no specific configuration for the search function necessary, but you can customize it using a variety of criteria.
Is the user interface customizable?
Are the browse options customizable?
Yes. Any facet you can get from your data is available for browsing.
What is the speed of deployment?
After the ten minute install? To customize it for your site you might customize the theme, and for a digital collection such as you describe, you'd likely have to build a harvester script to get the data from the source and parse it for Scriblio. The time for those can vary greatly, but there are a lot of examples to start with.
Can you extract data for future migrations? If yes, in what format?
Wherever you get your cataloging data is probably your best source if you were to migrate elsewhere, but there is a lot of great data inside Scriblio, especially the comments. That said, you can get data out via RSS and Atom, and export the contents of the collection (including the comments) as XML. You can also extend Scriblio to output data in other formats (HKUST built OpenSearch support) and verything is stored in a MySQL database, so you can always extract the data from there. We don't have one yet, but I've got plans to build an OAI interface too.
Does it support the following data types: EAD? TEI? Descriptive metadata (what kinds)? Preservation metadata? Structural metadata?
Does it support other formats (sound, video, pdf, etc)?
Content is content is content.
Okay, so those answers are flip, but Scriblio doesn't care what kind of data or what kind of content are in it. It's a big truck.
Support? Can the user fix problems or do we have to wait for fix from Scriblio? If Scriblio, how long is the avg. wait?
Scriblio is free, open source software.