About Question2Answer (Q2A), a popular open source platform for Q&A websites, built on PHP and MySQL.

1. Question2Answer
Dr Gideon Greenspan
gidgreen.com

2. Inspiration (1)
Dr Gideon Greenspan Question2Answer — Slide 2 gidgreen.com

3. Inspiration (2)
Dr Gideon Greenspan Question2Answer — Slide 3 gidgreen.com

4. Question2Answer
• “free open source platform for Q&A sites”
• PHP / MySQL
• Installation modeled on WordPress
– Create database
– Enter database details
– Upload files
– Go to web page
Dr Gideon Greenspan Question2Answer — Slide 4 gidgreen.com

5. Q2A Contributors
• Core only me (my choice)
• Democratic (mostly) roadmap
• 20 localizations
• 10 themes (mostly not good)
• 50 plugins
– 30 by one person
Dr Gideon Greenspan Question2Answer — Slide 5 gidgreen.com

6. Live Q2A sites
7,000
6,000
5,000
4,000
Sites
3,000
2,000
1,000
0
Jan 11 May 11 Sep 11 Jan 12 May 12 Sep 12
Dr Gideon Greenspan Question2Answer — Slide 6 gidgreen.com

7. Example 1: Frageee.de
34,994 questions
3,891 registered users
Dr Gideon Greenspan Question2Answer — Slide 7 gidgreen.com

8. Example 2: Orange Israel
7,650 questions
1,160 registered users
Dr Gideon Greenspan Question2Answer — Slide 8 gidgreen.com

9. Example 3: Propongo
3,886 “proposals”
3,869 registered users
Dr Gideon Greenspan Question2Answer — Slide 9 gidgreen.com

10. Example 4: PokeBase
12,195 questions
7,048 registered users
Dr Gideon Greenspan Question2Answer — Slide 10 gidgreen.com

11. Aggregate Users
600,000
500,000
400,000
300,000
Users
200,000
100,000
0
Jan 11 May 11 Sep 11 Jan 12 May 12 Sep 12
Dr Gideon Greenspan Question2Answer — Slide 11 gidgreen.com

12. Comparison (Sept 2012)
Question2Answer Stack Exchange
(excluding spammy sites) (excluding Stack Overflow)
Sites 6,036 89
Sites >1k Qs 73 61
Questions 634,053 841,790
(visible to Q2ABot)
Users 501,076 929,948
(registered only) (registered and unregistered)
Languages 40 1
Dr Gideon Greenspan Question2Answer — Slide 12 gidgreen.com

13. Size of Core Codebase
50 1.5
40
1.4
30 1.3
1.2
kLOC
1.0
20
10 MVP
0
Sep 09 Mar 10 Sep 10 Mar 11 Sep 11 Mar 12
Dr Gideon Greenspan Question2Answer — Slide 13 gidgreen.com

14. Lesson 1 — Licensing
http://osrc.blackducksoftware.com/data/licenses/
Dr Gideon Greenspan Question2Answer — Slide 14 gidgreen.com

15. Lesson 2 — Plugins
https://github.com/NoahY/q2a-badges
Dr Gideon Greenspan Question2Answer — Slide 15 gidgreen.com

16. Lesson 3 — Ecosystem
Dr Gideon Greenspan Question2Answer — Slide 16 gidgreen.com

17. Lesson 4 — Keep it Obvious
SELECT BINARY name AS name FROM …
(one query, less latency, but worse)
SET NAMES utf8
SELECT name FROM …
(two queries, more latency, but better)
Dr Gideon Greenspan Question2Answer — Slide 17 gidgreen.com

18. Lesson 5 — Eye candy
Dr Gideon Greenspan Question2Answer — Slide 18 gidgreen.com

19. Exit strategy
Dr Gideon Greenspan Question2Answer — Slide 19 gidgreen.com