ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.

iDempiere - iDempiere Business Suite ERP/CRM/SCM done the community way.

MinuteDock - Web-based time tracking software designed to integrate with the Xero accounting package.

DataNote ERP - DataNote ERP is a complete ERP solution built for multiple industries such as construction, engineering, food and beverages, metal processing, and healthcare, among others.

fusebill - Fusebill is the leading recurring billing and subscription management software for businesses. Try Fusebill for subscription billing made easy!

PracticePanther - PracticePanther offers CRM, invoicing, time tracking and communication solutions for law firms.