open source
Open source describes software whose underlying foundation (its source code) is available to the public. All users can view, alter, and redistribute open-source software so long as they abide the conditions set out by the license under which it is distributed. Popular open-source utilities include MySQL, phpBB, and WordPress.

order management system
With AT&T Yahoo! Merchant Solutions, you can use our order management system to process your orders online, which makes it easy to authorize, reauthorize, and settle shipped orders or process refunds. You can also quickly access one order, or a range of orders, and see detailed information about each order, including billing and address information, packing instructions, and order confirmations. Learn more.

order notifications
If you have a Merchant Solutions plan, you can choose to receive order notifications via email or fax. The fax option is particularly convenient if you're not online all the time, but want to ship and process customer orders as soon as they arrive. Please note that the fax option is available only in Merchant Enhanced and Merchant Premium plans. Learn more about receiving orders.