There are hundreds of different combinations of e-commerce models and accounting systems in the small business sector-- too many to do justice to, on this website. New services emerge literally every day.   see http://www.gldialtone.com/links.htm

• Web Storefront software or e-commerce service providers which provide 'connectors' to accounting packages
• Midrange accounting systems Solomon and Great Plains that offer integrated storefronts and ecommerce modules, as well as remote access by Citrix and by web interfaces.
• Replication solutions, enabling full-speed off-line functionality in a standalone accounting package, with replication or other background daemon pushing/pulling data to the Hosted Web GL
• Traditional FTP with modern tools:  for example, enabling CPA to use the data file of desktop software such as a Quickbooks QBW file for a while, then send it back.
• Traditional remote control: dialup PC Anywhere: You login, use the system a while until the session crashes.
• New remote control: e.g. accounting software on Citrix, Win2000 Terminal Server, or  NewMoon etc. over a DSL connection.
• Traditional Client/Server: You open the accounting system and run a fine grained connection to an RDBMS over the internet (not fun-slow.).
• Java Client/Server: You open the accounting system and run a fine grained connection to a Java application server over the internet with Java Applets (even less fun.).
• Linux or unix versions of traditional Client/Server: you either run terribly spartan character interface very nicely, basically with AppGen or telnet, or you run GTK or other X GUI, slowly over the internet.
• Telnet to mature unix or mainframe accounting systems.  This can be very functional and practical other than limitations on reporting, lack of ecommerce ability etc.
• Web modules such as timesheets or corporate purchasing desktops and portals
• ISPs hosting storefronts as service providing transaction files for import to standalone packaged software
• Web storefront software available for purchase, which provide ASCII integration to standalone packaged software
• etc. etc. etc. see what I mean?