What powers htdp.org?
Last seen Jun 2026 · 7 technologies across 6 categories
Caching
Varnish
since Jun 2020
CDN
Fastly
since Jun 2020
Google Workspace
since Aug 2022
Mailgun
since May 2024
Operating systems
Debian
since Apr 2018
PaaS
GitHub Pages
since Jun 2020
Web servers
Top search keywords
| Keyword | Position | Est. monthly visits |
|---|---|---|
| how to design computer programs | #1 | 79 |
| htdp | #2 | 23 |
| how to design programs second edition | #1 | 9 |
| how to design computer programs | #7 | 7 |
| how to design programs second edition | #3 | 3 |
| htdp | #8 | 3 |
| program design book | #6 | 2 |
| to designing | #72 | 0 |
| unquoting | #77 | 0 |
| what is a design program | #46 | 0 |
| what is design programming | #61 | 0 |
| what is the purpose and function of an accumulator | #50 | 0 |
| what is the primary function of an accumulator | #59 | 0 |
| scheme books | #58 | 0 |
| programming designs | #87 | 0 |
| programming design systems | #77 | 0 |
| program design books | #85 | 0 |
| is 1/4 a natural number | #73 | 0 |
| accumulator variables | #21 | 0 |
| generative recursion | #44 | 0 |
| how to design programs pdf | #57 | 0 |
| htdp | #86 | 0 |
| htdp | #78 | 0 |
| htdp | #74 | 0 |
| htdp | #60 | 0 |
The site's top keywords in Google (US), with the visits each one is estimated to bring per month.
Top backlinks
Top links pointing at the site, one per source domain, strongest first. The anchor text opens the page carrying the link.
Audience
- 78% desktop
- 22% phone
United States
Countries where the site has Chrome traffic, strongest markets first.
Open Page Rank
5.88 / 10 · ranked #118,824 of all domains
256 referring domains · OpenPageRank
Search traffic
130 est. monthly organic visits (US)
28 keywords in Google's top 30
Core Web Vitals
| LCP | 0.8 s |
| INP | 25 ms |
| CLS | 0 |
| TTFB | 300 ms |
Real user p75, Chrome UX Report, Jun 2026.
Page
- CDN: Fastly
- Weight: 0.1 MB · 5 requests
Homepage as crawled by the HTTP Archive, Jul 2026.
Subdomains
| Host | Techs |
|---|---|
| htdp.org | 5 |
| www.htdp.org | 2 |