This page is about the "Software Application" proposal for schema.org, as discussed in the Web Schemas group.
The bulk of the proposal is (currently) in a PDF; see attached file.
SoftwareApplication schema.org proposal
It defines a use of several properties of Thing and CreativeWork for use with Software Applications. It defines a class SoftwareApplication with 20 properties, and a couple of subclasses, MobileApplication and WebApplication (each with just one custom property). The proposal comes from work on Google Rich Snippets; see Google's documentation on earlier drafts of the vocabulary. It also defines an enumeration of various sub-types (e.g. ShoppingApplication, SportsApplication, FinanceApplication); these might remain Snippets-only vocabulary if it isn't agreed to include these in schema.org.
Proposal PDF: File:Schema.org-SoftwareApplicationsV2.pdf
See also: announcement on public-vocabs list.
Note that the original proposal here included a set of types. These are not currently scheduled to be added to schema.org, although it should (work-in-progress, e.g. see external enumerations) be possible to reference them. For convenience, here is a copy of the list:
GameApplication, EntertainmentApplication, BusinessApplication, MultimediaApplication, DeveloperApplication, DriverApplication, EducationApplication, HealthApplication, TravelApplication, FinanceApplication, SecurityApplication, BrowserApplication, CommunicationApplication, DesktopEnhancementApplication, DesignApplication, HomeApplication, SocialNetworkingApplication, UtilitiesApplication, ReferenceApplication, SportsApplication, ShoppingApplication, MedicalApplication, OtherApplication.