Free how to start a small business software for linux

Web Business Pro is a Web application designed for everyday business activities. The project includes support for customer lists, inventory, receipt printing, and accounting. Fully featured search functions and filters make it easy to find what you need quickly.

Kumula is designed to become a complete software suite for business needs. Started as software for consultants, it is flexible enough to be used by almost any class of business. Kumula Business Suite provides a small CRM (Clients) and a Mini-DMS (Documents), enhanced by some other applications. Everybody is invited to use it or enhance it.
Kumula is written in Qt (http://www.trolltech.com/products/qt/), PyQt and Python using the fabulous Eric3 development environment.
Enhancements:
- This is the last stable release before Ill port it to Qt4 (as "Kumula2"), so I feel free to call it "1.0".
- The whole suite is becoming bigger and bigger, so now its time to split it. This is the base package with the central Kumula library and the most important applications. The package contains the following programs:
BizCalc:
- The modular designed calculator tool, coming with a spartanic RPN calculator and an unit conversion module
Clients:
- The client/customer management application, with many improvements (like individual client attributes) and the modules "Info" (logo+description), "Contacts" (for managing contact persones, addresses and communication data) and "Tickets" (for letting the users talk about a client like on a web forum)
Configurator:
- The central configuration utility, to setup the database access and the user interface (menus, icons, ...) of all Kumula applications.
Users:
- A small tool for managing the people using Kumula.
- Further application will be provided in separate packages for easier maintenance and faster bugfixes and updates.

Strictly Invoices is an application for the small business owner who wants to send out invoices!
Important Note: You may need to make the file executable by changing the properties or running the command:
chmod 755 invoices
Main features:
- Save multiple companies
- Create HTML invoice
- Save Customer Data
- Create Product List
- Print to PDF
- Save Invoices
- Email
- Change any title on the invoice to your needs (Registered Version)

Auction Business Manager is a tool that helps you keep track of income and expenses for your online auctions, e.g. with eBay.
Auction Business Manager also color codes your listings so that you can easily see who you need to ship packages to and who still needs to pay.
There is a statistics page that tells you, by month, what your expenses were, what your income was, and how much profit you made, so its easy to see how well your business is growing.
Main features:
- Easy installation - just unzip, upload, install a single table into your MySQL database and youre ready to rock!
- Simple, intuitive interface - Auction Business Manager is structured so that its very easy to make changes to and update your listings.
- Ongoing Balance Sheet - Worried that you might be spending more than youre making? No problem, just keep track with Auction Business Manager, and compare how youre doing from month to month.
- Its Online - Once you install Auction Business Manager on your hosting account, you can access it from any computer.
- Password Protected - Auction Business Manager uses a simple login system to keep unwanted visitors and meddlers out.

Caravan Business Server is an extremely easy to use comprehensive development and deployment framework which has been used to build Enterprise wide, mission critical Web-based applications.
It includes, as a seamless integrated package, an easy to use Scripting Language, Search Engine, Database Engine, a Web Server and a Communication Server, which makes it a 1-Tier Architecture.
Caravan Business Server is currently available on Linux. Once an application is developed on any OS, the same can be simply redeployed on any other OS without making any changes.

W3MAIL - fast and small web-mail client written in PHP5. It provides easy webmail access to IMAP accounts and has very few requirements to install.
Main features:
- multi-language support
- simple contacts manager
- MIME attachments
- displays HTML messages
W3MAIL supports leading open-source database engines:
- PostgreSQL
- MySQL.
Translations:
- English
- Russian.
User Interface:
- Web-based.