Forums in the Open Source Niche

1. ABestWeb Affiliate Marketing
Forum has 136,532 topics.
http://www.abestweb.com/forums/  

2. Mindless Self Indulgence
Maintenance Mode
http://www.mindlessselfindulgence.com/board/  

3. DIYstompboxes.com
DIYstompboxes.com - Index
https://www.diystompboxes.com/smfforum/  

4. Joomla!
Just made it into the top 50!
https://forum.joomla.org/  

5. Chronicle Forums
Chronicle Forums - Index
http://chronicle.com/forums/  

6. Whitby Sea Anglers Forums
Whitby Sea Anglers Forums - Index
http://www.whitbyseaanglers.co.uk/forum/  

7. The Sewing Academy @ Home
The Sewing Academy @ Home - Index
http://www.thesewingacademy.org/  

8. West Coast Connection
West Coast Connection Forum - Index
http://www.dubcc.com/forum/  

9. schoolofevolutionaryastrology.com
School of Evolutionary Astrology Message Board - Index
https://schoolofevolutionaryastrology.com/forum/  

10. Java Forums at the Big Moose S
https://www.coderanch.com/forums/  

11. Keeptouch Community Portal
Keeptouch Community Portal is an online community based in Singapore, offering a place for exchange of ideas and information in a wide range of topics in the form of forum discussions and Internet...
http://forums.keeptouch.net/  

12. Mens Tennis Forums
Forum has 56,179 members.
http://www.menstennisforums.com/  

13. Daz 3D Forums
Daz 3D, 3D Models, 3D Animation, 3D Software
https://www.daz3d.com/forums/  

14. www.divorcesource.com
https://www.divorcesource.com/ubbthreads/  

15. Start Backpacking Travel
Use the backpacking forums to get answers for your next trip! Find travel jobs posted, writing opportunities, and more. See two excellent travel forums.
https://www.startbackpacking.com/forums/  

16. RuneScape Community
The RuneScape Wiki is a RuneScape database that anyone can contribute to. Includes skills, quests, guides, items, monsters and more.
http://forums.zybez.net/  

17. 3D Realms Forums
This is a discussion forum for fans of Apogee / 3D Realms to talk about various game related topics.
https://forums.3drealms.com/vb/  

18. Techist - Tomorrow's Technology Today
Forum has 83,688 members.
http://www.tech-forums.net/forums/  

19. Wilders Security Forums
Community Based Discussions about Online Privacy, Security and Data Protection
http://www.wilderssecurity.com/  

20. sternfannetwork.com -&nbs
sternfannetwork.com is your first and best source for all of the information you’re looking for. From general topics to more of what you would expect to find here, sternfannetwork.com has it all....
http://www.sternfannetwork.com/xen/index.php?forum/  

21. Hip Hop Universe
Forum has 296,389 topics.
http://www.hiphop-universe.com/underground/  

22. Siccness Network
Forum has 69,267 members.
http://siccness.net/vb/  

23. TableTennisDaily
TableTennisDaily sharing Table Tennis content to the World. All the Latest Videos, World Tours, Articles, Discussion's, reviews and more!!
https://www.tabletennisdaily.co.uk/forum/forum.php  

24. Getbig Bodybuilding, Figure an
Getbig Bodybuilding, Figure and Fitness Forums - Index
https://www.getbig.com/boards/  

25. AnandTech Forums: Technology, Hardware, Software, and Deals
Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
http://forums.anandtech.com/  

26. UKCampsite.co.uk
UKCampsite.co.uk Camping and Caravanning Forums. The UK's largest and busiest forums for caravans and camping and motorhomes
https://www.ukcampsite.co.uk/chatter/  

27. CryptocurrencyTALK
Since 2013, CryptocurrencyTALK forum has been the source for advice on what crypto to mine, cryptocurrency technical details, new altcoin launch announcements, and advice from trusted members of...
https://cryptocurrencytalk.com/  

28. AppraisersForum.com
Real estate appraisers forum that is open to all. Discuss real estate appraisal on these real estate appraiser forums.
https://appraisersforum.com/forums/  

29. Open Photography Forums
Imaging to hold up a lantern to ourselves and the planet we’ve claimed dominion!
https://openphotographyforums.com/forums/  

30. RunningForums.com
This website is for sale! runningforums.com is your first and best source for all of the information you’re looking for. From general topics to more of what you would expect to find here,...
http://www.runningforums.com/index.php  

31. HardwareCentral Forums
Hardware Central Forums are your source for computer hardware discussions, with tips and tricks on buying, upgrading and maintaining your laptop, notebook and desktop PC or peripherals. Topics...
http://www.hardwarecentral.com/forum.php  

32. vibalt.com
Recent Discussions (1/1) - Kunena - Lithuanian (LT)
https://vibalt.com/lt/forum  

33. Honda-Acura.net
An unofficial Honda and Acura discussion forum
https://www.honda-acura.net/forums/  

34. Overclockers UK Forums
Overclockers UK Forum powered by Xenforo
http://forums.overclockers.co.uk/  

35. VolleyBall
Volleyball Forum is a free Volleyball enthusiast forum. Discuss all aspects of Volleyball from AVP tour, International competition to Collegiate Volleyball. Registration is FREE!
http://www.volleyballforum.com/  

36. MMA News
The official forum site of MMANews.com, Forums.MMANews.com is now BACK online after a down-time of over 8 days.All members of the MMANews.com forums at
http://www.mmanews.com/forums/  

37. North Shore Mountain Biking Fo
Quality mountain bike editorial, photos, videos and news from a North Shore perspective.
http://bb.nsmb.com/  

38. Rolex Forums
Rolex forum - Rolex discussion forum, Rolex news, Rolex features, Rolex gallery, Rolex resources, Rolex reviews, Rolex watches,Rolex sales,Tudor,Panerai,Omega
http://www.rolexforums.com/  

39. The Watch Forum
Welcome to the Watch forum where you can discuss modern and vintage watches with other collectors and enthusiasts or just let off steam in the more open forums.
https://thewatchforum.co.uk/  

40. EnviroLink Forum
Forum has 67,673 posts.
http://www.envirolink.org/forum/  

41. Steam Users' Forums
This is a discussion forum powered by vBulletin. To find out about vBulletin, go to http:www.vbulletin.com .
http://forums.steampowered.com/forums/  

42. Harry Potter Friends
Harry Potter Cursed Child and Fantastic Beasts movie news, Rumors, Forums, Images, Role-Playing, Fan-Fiction, Fan-Art, Movie and Books Information and more!
https://www.snitchseeker.com/  

43. GSM-Forum
Welcome to gsm-forum, here you find all infos about android, windows mobiles, iphones, flashing, repair, unlocking, root, development software, firmwares.
https://forum.gsmhosting.com/vbb/  

44. Sell & Trade Game Items | OSRS Gold | ELO
Forum has 364,377 members.
http://www.sythe.org/  

45. DR1 Dominican Republic Forums
The Dominican Republic's most up to date source for news and travel information.
http://www.dr1.com/forums/forum.php  

46. Forumosa
Taiwan's largest and most active Taiwan-oriented global online community in English
http://www.forumosa.com/taiwan/  

47. DSL Reports
ISP discussion forums, broadband news, information and community
https://www.dslreports.com/forums/all  

48. MrExcel Message Board
Your One Stop for Excel Tips & Solutions
http://www.mrexcel.com/forum/forum.php  

49. Apolyton Civilization Site
Just missed out on a spot in the top 25.
https://apolyton.net/forum.php  

50. GP Forums
New Zealand's video gaming community-Games Discussion-Tech Discussion-Open Discussion-Administration-VIP Lounge-Game Communities-Battlefield-Counter-Strike-Dota 2
http://www.gpforums.co.nz/