Multi-vendor e-commerce sites are really popular.

Sites such as eBay, Etsy and AliBaba have enormous reach and support with 100,000's of sellers on just one site.

However, multi-vendor sites are also really difficult to build and maintain. E-commerce itself is difficult enough, but when you multiply the number of transactions and vendors, you multiply all of the potential issues.

Still, we often get asked how to set up a multi-vendor site. For our members and our readers, here are options for building a multi-vendor site with open source software.