One of the most popular Linux distributions available, Ubuntu comes in both desktop and server versions. And unlike Windows, Linux distributions come with a huge library of software included, so you'll have access to all the apps you'll need right awayand they're free.
Calling itself "the universal operating system," Debian runs on mobile systems, supercomputers and everything in between. Like Ubuntu, it's easy to use, but while Ubuntu is aimed at Linux novices, Debian tends to be used by people with a little bit more Linux experience.
This tool lets you create PDF files from any application that can print. The latest version even includes advanced features like encryption, digital signatures and PDF/A archive file creation. Operating System: Windows.
With nearly 10,000 installations per month, Openbravo POS is one of the more popular open source POS solutions available. It integrates with Openbravo ERP and supports a wide range of point-of-sale hardware. Although the Web site pushes the commercial editions of Openbravo products, you can still download the source code for free. Operating System: Windows, Linux, OS X.
49. Lemon POS Replaces: QuickBooks Point of Sale, AccuPOS
Lemon stores information in an open source MySQL database and offers a simple, safe, customizable POS solution. With role-based permissions, it's suitable for small or mid-size businesses, and it's also used successfully by micro-businesses. Operating System: Linux.
50. Floreant POS Replaces: QuickBooks Point of Sale, AccuPOS
This point-of-sale solution for restaurants makes it easy to take orders, track tables, settle tickets, balance the drawer, track staff and more. It's used by a number of well-known restaurants, including Denny's. Operating System: OS Independent.
Specifically designed to replace Microsoft Project, OpenProj opens both Project and Primavera files. It can create Gantt Charts, Network Diagrams (PERT Charts), WBS and RBS charts and more. Operating System: Windows, Linux, OS X.
52. Open Workbench Replaces: Microsoft Project, Oracle Primavera
Owned by CA, Open Workbench lets you schedule projects manually or automatically, create and manage subprojects and dependencies, associate guidelines with features, assign resources, and track progress with a variety of charts. The Web site includes a detailed comparison of the relative merits of Open Workbench and Microsoft Project and explains which tool works better in various situations. Operating System: Windows.
53. GanttProject Replaces: Microsoft Project, Oracle Primavera
While not quite as robust, GanttProject offers many of the same features as OpenProj and Project. It tracks tasks, resources, milestones, dependencies, etc. Operating System: Windows, Linux, OS X.
You can use Zentyal as a gateway, infrastructure manager, unified threat manager, office server and/or a unified communication server. The 2.0 version (currently in beta) will add Web server and FTP server capabilities, as well as many other improvements. It's based on Linux.
When your small business grows to the point that it becomes difficult to track employee time with paper forms or spreadsheets, TimeTrex offers a step up. It handles employee scheduling, attendance, job costing and payroll. Operating System: Windows, Linux, OS X.
56. eHour Replaces Replicon, Tenrox Timesheet
This Web-based app is designed for small firms of consultants, freelancers, lawyers, etc. who charge by the hour. It can track multiple employees working on multiple projects for multiple clients. Operating System: Windows, Linux, OS X.
An excellent option for first-time Web site creators, NVU walks you through building a Web site in three simple steps. It aims to make creating Web pages as easy as using a word processor. Operating System: Windows, Linux, OS X.
58. Kompozer Replaces: Adobe Dreamweaver, Microsoft Expression Web
Very similar to NVU, Kompozer offers a WYSIWYG editor that feels a lot like the Dreamweaver interface. It claims to be "the easiest-to-use, most powerful Web Authoring System available." Operating System: Windows, Linux, OS X.