The following Open-Source software trials are available here :-

1. AllocPSA (1.9.0) [db0] - A Professional Services Automation application that helps you take care of your projects, people, time sheets, invoicing and clients. (http://sourceforge.net/projects/allocpsa).
   • Clean, simple interface. Manages Clients -> Projects -> Tasks/Activities -> Timesheets -> Products & Invoices.
     
     
2. Web2Project (3.4.0) [db1] - A Free Open Source business-oriented Project Management System (PMS) built for the future. (http://web2project.net/).
   • Looks very promising.  Has a good database structure with a hierarchical relationship between the tables/entities, and the UI is clean & well thought out.
     
     
3. vTiger (7.3.0) [db2] - CRM system based on SugarCRM.
   • Simpler than SugarCRM, but has all the features any small to medium business would need. (https://www.vtiger.com/open-source).
   • This is the latest production version...
     
     
4. AllocPSA (1.8.9 Dev) [db3] - A Professional Services Automation application that helps you take care of your projects, people, time sheets, invoicing and clients. (http://sourceforge.net/projects/allocpsa).
   • Clean, simple interface.  Manages Clients -> Projects -> Tasks/Activities -> Timesheets -> Products & Invoices.
   • This is my own modified version of 1.8.9 ...
     
     
5. AllocPSA (1.9.0 Dev) [db4] - A Professional Services Automation application that helps you take care of your projects, people, time sheets, invoicing and clients. (http://sourceforge.net/projects/allocpsa).
   • Clean, simple interface.  Manages Clients -> Projects -> Tasks/Activities -> Timesheets -> Products & Invoices.
   • This is my own modified version of 1.9.0 ...
     
     
6. GLPI (9.5.3) [db5] - An Information Resource-Manager with an additional Administration Interface. You can use it to build up a database with an inventory for your company (computer, software, printers, etc.). It has enhanced functions to make the daily life for the administrators easier, like a job-tracking-system with mail-notification and methods to build a database with basic information about your network-topology. (http://www.glpi-project.org).
   • More of a Help Desk & Inventory/Asset manager than a Client/Projects manager.
     
     
7. FengOffice (3.8.4) [db6] - Web-based Software that integrates Project Management, Client Relationship Management, Billing, Financing, among other features that help you efficiently run your Professional Services Business. (https://www.fengoffice.com).
   • Release version 2.x.x of Feng Office - contains significant improvements over previous versions.
     
     
8. qdPM (9.1) [db7] - Web-based Project Management Software that integrates Task Management, Time Tracking, Invoicing and Support Tickets (http://www.qdpm.net).
   • In continuous development, looks promising...
     
     
9. dotProject (2.2.0) [db8] - A free and open source project management system. (https://dotproject.net/).
   • Currently being updated, but development is slow...
     
     
10. Dolibarr (12.0.3) [db9] - A modern and easy to use ERP CRM web application to manage your business (contacts, invoices, orders, products, stocks, agenda, emailings, etc...). (https://www.dolibarr.org/).
    • This is the latest production version...