| Security & Bot Defense | |
| reCAPTCHA Google service distinguishing humans from bots to block spam | 12.9M sites |
| Web Servers & Operating Systems | |
| Apache HTTP Server Long-established open-source web server software | 67.2M sites |
| CentOS Linux distribution commonly used on web servers | 768.4K sites |
| OpenSSL Cryptography toolkit implementing TLS and SSL protocols | 1.8M sites |
| Languages & Back-End Frameworks | |
| PHP Server-side scripting language powering a large share of websites | 89.1M sites |
| Front-End Frameworks & UI Toolkits | |
| Bootstrap Popular CSS and component framework for responsive layouts | 36.7M sites |
| JavaScript Libraries & Widgets | |
| jQuery Widely used JavaScript library simplifying DOM manipulation, events, and AJAX | 90.4M sites |
| other | |
| Gagnaveitan | 5 sites |
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