Welcome!
I am Demetris Kikizas and this is my online notebook for recipes and how-tos. The recipes are for web development and related topics — not food! Have a good time!
Recent posts
How to block Googlebot impersonators
8 November 2025
Apache snippets to block fake Googlebots
SEO and SEM badness
4 November 2025
SEMrush
PNG and modern image formats: A comparison of lossless image compression
15 October 2025
A benchmark of lossless image compression comparing PNG with AVIF, HEIF, JPEG XL, and WebP for fourteen graphics images
Recent updates
oxipng and friends: A comparison of PNG optimization tools
Updated 4 October 2025
A comparison of PNG compression with optipng, oxipng, and FileOptimizer; also includes results of lossless conversion from PNG to WebP
PHP versions in Linux distributions
Updated 7 September 2025
Debian manpages
Updated 10 June 2024