O2B is the most powerful 100% Force.com Billing and Subscription management solution on the appexchange. Volume billing, prorated, anniversary bill, usage metering and rating, recurring & one-time charges, credit card integration. The only available system to include Ordering, Invoice, and Payments.
TOM(Telecom Order Mgmt, v1.3) is designed to be used by Telco vendors to do Product Modeling, Manage Sales Orders for Wireline, Wireless, IP, Data and other Managed services.
Sequencer is 100% Force.com Native, able to be used with any salesforce object, graphical, drag and drop editor. Design and execute business processes without the need for a salesforce engineers or advanced administrator skills. Sequence tasks and activities to non-salesforce users.