BillGrid.com - BillGrid is an easy to use online invoicing, billing and expense management system that will save you time with tracking clients projects, expenses, invoices and payments.

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

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

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.

Elorus - A super-easy online invoicing & time tracking software

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