The REAXML Import for EZ Realty component is deployed as a package containing a Joomla component install and a library install.
I did end up using PHPUnit to do test driven development running automated tests for the library classes. The library classes do the database work, the mapping and other processing to create and update the EZ Realty table records and process and register the listing picture files.
The component has an admin site part and a main site part. The admin site part can do the import as well as the main site part. The main site part is available as a menu item. Fairly standard stuff.
I use AJAX to trigger the import and to refresh some directory listings I have on the page. Seeing it's basically a file processing tool, I thought showing what was in the directories someone would think was useful.
I've spent the past week and half since then setting up this web site so I can spread the love, and hopefully monetise the effort maybe. I had to charge the client a minimal amount for the development effort otherwise, well, it wouldn't have been done. I've established paid subscription on this site using SP Digital Subscriptions, and a support ticketing system using Macrotone Consulting's Issue Tracker.
I had to make some minor adjustments to the site CSS to get the subscription stuff looking right for me. Still some work to be done on the ticketing system styling. But it can wait I hope. I need to get it to a point where I can leave it for a few days and I can focus on some marketing material work for the shop.
I'll need to look at registering the component on the Joomla extensions site I suppose. I don't expect it'll do me much good as the component fills such a tiny narrow space. But I guess I won't know till I put it out there.