A comprehensive roundup of web development and programming advent calendars for December 2025. The collection includes calendars covering HTML, performance optimization, accessibility, various programming languages (JavaScript, Python, Perl, C#, Java, F#), and coding challenges. Each calendar offers daily content throughout
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HTMHell Advent Calendar ( @matuzo @front-end.social )Advent of Code ( @ericwastl @hachyderm.io )24 Jours de Web ( @ParisWeb @mamot.fr )Performance Calendar ( @stoyan.org@bsky.app )JVM Advent ( @JavaAdvent )アクセシビリティ Advent Calendar 2025 ( @motchie )Selfhtml Advent ( @SELFHTML @bildung.social )Kodekalender ( @knowitnorge )Bekk Christmas ( LinkedIn: bekk )24 Days in Umbraco ( @24DaysInUmbraco )24 Pull Requests ( @24PullRequests @mastodon.social )Perl Weekly Challenge Advent ( @PerlWChallenge )Perl Advent Calendar ( @perladvent )C# Advent Calendar ( @mgroves )Raku Advent CalendarFestive Tech Calendar ( @_cloudfamily )IndieWeb Gift CalendarCSS Advent Calendar ( @stevenaharrison )F# Advent Calendar in EnglishadventJSSort: