There are a number of open source MicroApps that a person can use.  Following is a list of some of the more common applications and their functions:

Tasty – A program used for tagging. Twister – RNG for use in any statistical solution. Fozzy – Searching through text using the PostGRE SQL engine. Drinkme – Program to change the size of images and create thumbnails. Pubcookie – System for a lone signon. Gossip – A MicroApp developed to use a comment or discussion board system. Solr – Another search for text, but using Lucene. YARS – datastorage for Java and RDF/N3

MicroApps for Commercial Use Amazon S3 – Net-based storage that is built on the REST interface. Amazon SQS – Queue program to work with S3 on the REST platform. Captchas.net – Spam blocker for form submission and discussion boards.

Free MicroApps for Hosted Use Triplr – Creates RDF Triples based on URIs. Rst2a – Converts text to other formats. GeoNames – Looks up data about a location, including postal code, GPS positioning, and elevation. Mailhook – Email listener and forward service.