I believe you can run an enterprise on Open Source Software (OSS), and if you are starting a new company you should.

Big companies are very conservative. They confuse OSS with Freeware and think anything that you can use for free is "Worth what you pay for it". Very few use OSS and some have policies against it. Because of the way OSS is developed it is also highly adaptable. Can an enterprise be more innovative by using OSS and still maintain the support it needs?

New start-up businesses should be using open source. The ability to change the programs to meet the needs of their business model is paramount. OSS products often have a "community version" that can be used for free. The old questions of to "Build or Buy" should be answered "You should buy and build". Fee OSS software comes without support so hiring the right people to support your enterprise is crucial. Start-ups run on people. I'm saying these people need to have OSS talent.

These are all Open Source and ready to run your enterprise.

Human Resources

Orange HRM is the leading open source HRM and provides a flexible and easy to use HRM system.

The project was started during fall 2005 and the
first beta release was made in January 2006. Today OrangeHRM has users
worldwide enjoying a free, stable and highly usable HRM solution. The
system is backed by professional support and services as well as a fast
growing, receptive and knowledgeable worldwide open source community.
By building and leveraging this community of users, developers and
partners, the usability, scope and international adoption of OrangeHRM
is continuously being improved.

OpenVista
- manages electronic medical records. It has been deployed by several state and private employers and medical facilities around
the country. The open-source version of VistA, which is an enterprise grade
health care information system developed by the U.S. Department of
Veterans Affairs (VA) and deployed at nearly 1,500 facilities
worldwide.

Customer Management

SugerCRM is an innovative customer relationship management software
solution.

Customer are the core to every kind of business. You can, schedule appointments, link them to records and notes, organize your sales opportunities, build campaigns, track their success, manage customers send e-newsletters and automate customer e-mail communication.

Open For Business (OfBIZ) is Open Source ERP, CRM (Like Sugar), E-Business / E-Commerce , SCM, MRP,
CMMS/EAM and POS. Need I say more?

Why pay millions to Epicor, Oracle, Lawson, Infor or Microsoft when you can manage all your customers for the cost of the hardware and people to manage it.

OfBIZ can provide

• advanced e-commerce
• catalog management
• promotion & pricing management
• order management (sales & purchase)
• customer management (part of general party management)
• warehouse management
• fulfillment (auto stock moves, batched pick, pack & ship)
• accounting (invoice, payment & billing accounts, fixed assets)
• manufacturing management
• general work effort management (events, tasks, projects, requests, etc)
• content management (for product content, web sites, general content, blogging, forums, etc)
• a maturing Point Of Sales (POS) module using XUIas rich client interface
• and much more all in an open source package!

Data Management / Warehousing

Pentaho - Is business intelligence (BI) software for data integration, query, reporting, interactive analysis, dashboards and data mining. Pentaho is alrady being used by organizations like U.S. Naval Air Systems Command, Lifetime Networks and Terra Industries. Some people are shocked to learn this is Open Source software.

The first word in data processing is data. We move data, copy data, transform data, mediate data into new data and move it again. As a systems administrator I've written hundreds of programs to manipulate data in a automated fashion. When I learned about Pentaho I wondered where it had been all my life. Here is the video I found.

Check out this video about Running Pentaho on iPhone.

Pentaho is starting to get attention.

Zamanda - Amanda is a popular open source backup tool. ZAmanda is the chimerical version with a web interface. Amanda comes with may OpenSource operating systems and is said to be protecting more than half a million servers and
desktops running various versions of Linux, UNIX, BSD, Mac OS-X and
Microsoft Windows operating systems worldwide.

I feel ZAmanda big stright is it uses industry tape structures. (tar and dump) Because of this your data is recoverable, even without using Amanda tools. Your data is yours. You don't need to find your license or repurchase any software to recover your data in a desastor.

Zmanda’s innovations include technology to backup data from live applications and databases directly to a storage cloud.

Check out the Zamanda Demo.

Communications - Email and Phones

Zimbra - Is a complete replacement for Microsoft Exchange and Active Directory. It provides eMail, client messaging and collaboration, group calendaring, VoIP, shared contacts, web document management and authoring.

Zimbra offers Zimbra Mobile, which provides over-the-air "push" synchronization to smartphones as well as a Connector for BlackBerry Enterprise Server.

Zimbra is being used by companies like Yahoo, ComCast and me for customer email systems.

Astrec - Asterisk is the world's leading open source PBXi, telephony engine, and telephony applications toolkit. Offering flexibility unheard of in the world of proprietary communications, Asterisk empowers developers and integrators to create advanced communication solutions...for free.

Desktop Office Applications

Open Office
is a free cross-platform office application suite available for a number of different computer operating systems. It supports the ISO/IEC standard OpenDocument Format (ODF) for data interchange as its default file format, as well as Microsoft Office formats among others.

Every time Microsoft make a change to MS Office employees have to relearn where each feature have moved. The last update to MS Office was big. If your employees are going to have to learn something new my not have them learn Open Office. It is very close to the last release of MS Office. The next time you need to update your office productivity ivy software you will not have to pay for it twice.