Apps similar to Magento Marketplace Extension include Magento 2 Multi Vendor Marketplace Extension, which is open source but paid. Mercur is free. Other options are Magento 2 Marketplace Extension - Magebay.com. In total there are three E-commerce Systems like Magento Marketplace Extension for the web, self-hosting, Mac, Windows and Linux.
Instantly create your own multi vendor marketplace store from Apptha's Magento 2 Marketplace extension with free addons and 1 year free cloud hosting.
India
Mercur is the complete open-source platform to run your entire marketplace. It comes with a storefront for buyers, a vendor panel, an admin console, and integrations into your stack.
Poland
EU
Magento Multi Vendor Marketplace Extension will convert your magento store into Marketplace website like Amazon , Ebay , Etsy, Alibaba, Aliexpress
Vietnam