Midwestern Mac has been offering Apache Solr hosting for Drupal websites for the past three years, but this service has never been given too much attention or made easy to sign up for and use—until now!
Today we're announcing the re-launch of our service with a new website: Hosted Apache Solr.
The website was built on Drupal 7, and uses a custom base theme shared with Server Check.in (our server monitoring service built with Drupal and Node.js). We built a small payment integration module for PayPal subscriptions (though we're considering using Drupal Commerce, so we can use different payment processors more easily), and have built a very simple to use front-end for managing Solr core subscriptions.
If you don't know much about what Apache Solr can do for your site's search and listings, here's a one-sentence summary: Solr enables highly customizable and speedy content indexing, faceted and advanced search filtering abilities, and raw speed—indexing and searching are many times faster than database-backed search (like Drupal's default search or basic Views filtering).