Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community

Agilon One - Agilon One is a Nonprofit CRM software solution that connects and gathers information on constituents.

UseResponse - Open-source, self-hosted customer feedback software, live chat and helpdesk system that you can install on your server. Organize documentation using knowledge base and get feedback from social networks with centralized system

Little Green Light - Illuminating Data. Advancing Nonprofits.

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

Donorhut - Donorhut offers cloud fundraising software for charities and non-profits of any size.