Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
PTC Windchill - Windchill offers breakthrough Product Lifecycle Management (PLM) capabilities, unleashing more data to more stakeholders throughout your organization through a single source of truth for product data and processes.
WhenWorks - Mobile appointment scheduling
Enovia - ENOVIA offers product lifecycle management (PLM) solutions fostering innovation and operational excellence across industries.
Inspora - virtual chat-stylist for fashion advice.
Propel - Propel is a customer-centric PLM software built on Salesforce App Cloud platform.