Multi-Vendor On-Premises is a self-hosted marketplace builder that allows entrepreneurs to start large marketplaces and scale them easily. Comes with over 500 features, open source code and 1,700 live cases worldwide.
Dittofi Marketplace Solution - Build a custom marketplace in under 24 hours.
Camunda - The Universal Process Orchestrator
Sharetribe - Build your online marketplace business. You don't need a developer.
SyncTree - SyncTree is a SaaS-based Super Connecting Platform that connects any services you want
SmartEngage - Cross-channel autoresponder for marketing automation
jBPM - jBPM is a flexible Business Process Management (BPM) Suite.