Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets

Constant Contact - Constant Contact offers email marketing, social media marketing, online survey, event marketing, digital storefronts, and local deals tools.

Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform

Omnisend - Omnisend - Marketing Automation for Ecommerce provides the omnichannel approach for sales-driven marketers that have outgrown the generic email marketing platforms.

pretix - pretix helps you to sell tickets for your event in an easy way. It supports multi-lingual events and provides a wide range of features