1. Discord: A popular platform for gamers, Discord offers text, voice, and video communication along with customizable servers and channels.

2. Slack: Slack is a cloud-based collaboration hub ideal for teams and businesses. It allows for document sharing, integrations with various tools, and customizable channels.

3. Facebook Groups: Facebook Groups is a great tool to create communities around shared interests where members can share content, discuss topics, and organize events.

4. LinkedIn Groups: LinkedIn Groups enable professionals to create specialized networks around industries, job roles or specific interests.

5. Reddit: Reddit is an online platform consisting of various forums called subreddits where users can share, discuss and upvote content on specific topics.

6. Mighty Networks: Mighty Networks allows creators to build niche communities with customizable features like member profiles, groups, events, and online courses.

7. Circle: A modern community platform designed for creators, Circle facilitates member interaction through discussion boards, zoom meetings integration, direct messaging, and more.

8. Tribe: Tribe is a beautifully designed community platform that offers easy integration with your website or app while providing various customization options like branding and domain mapping.

9. Vanilla Forums: Vanilla Forums is perfect for businesses wanting a feature-rich and customizable community experience that can be scaled to any size.

10. Zimbra Collaboration Platform: Zimbra enables you to manage your email, calendar, tasks, chat conversations or social media accounts in a collaborative environment with multiple applications.

11. Telligent Community: Telligent Community provides seamless integration with Microsoft SharePoint as well as a wide range of collaboration tools to create corporate communities.

12. Invision Community: Invision offers powerful features like forums, galleries, blogs and calendars designed for pro-level communities with extensive customization options available.

13. Yammer: Yammer is an enterprise social networking service used by thousands of businesses as their private intranet, with a strong focus on collaboration and communication within the company.

14. Hivebrite: This all-in-one community management platform caters to various industries, empowering businesses to build, grow and manage online communities easily.

15. Khoros Community: Khoros Community helps you provide consistent customer experiences by enabling seamless interaction between customers, employees and partners.

16. Ezcape Chat: Ezcape Chat is a real-time chat solution specifically designed for live broadcasts and streaming platforms, enriching viewer engagement during streams.

17. phpBB: A free and open-source PHP-based forum software, phpBB offers self-hosted online community options with a powerful feature set and a large support network.

Each of these platforms brings its unique features and advantages to help your online community thrive. Evaluating your goals, target audience, and budget will help determine which platform is best suited for your needs.