Esri ArcGIS - ArcGIS provides contextual tools for mapping and spatial reasoning so you can explore data & share location-based insights. ArcGIS is the heart of the Esri Geospatial Cloud. Try ArcGIS for free with 21-day trial.
Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.
QGIS - QGIS is a desktop geographic information system, or GIS.
Morse - Create, shout out, and discover nearby events in real time
Geopointe - Geopointe enables Salesforce users to gain spatial insights via maps and apply geography to business processes.
Upcoming.org - A simple way to share and discover interesting events