Office Engine is an MIT-licensed JavaScript library for viewing and editing DOCX, XLSX, and PPTX files directly in a browser, without sending documents to a server. Its central idea is to make large office files usable quickly by loading content progressively: it uses HTTP range requests and lazy ZIP access where possible, parses XML in a Web Worker, and renders only visible pages, cells, or slides. The project reports that a 24.8 MB spreadsheet with 300,000 rows and 12 columns shows its first content in about 330 milliseconds and loads fully in roughly two seconds. Benchmarks were run in headless Chromium on Apple M-series hardware.
The editors support document text and formatting, spreadsheet cells and formulas (134 functions), and presentation text, shapes, images, and slideshows. Saving regenerates only changed file components, preserving the original bytes for untouched parts. Additional features include CSV import, PDF and other exports, printing, and real-time collaboration with cursors, avatars, and offline edits that sync after reconnection. Developers can embed it as a React component or use a hook, vanilla JavaScript mount, or web component. The repository provides a live demo with large sample files and upload-your-own-file support; its documentation also describes supported formats and limitations.
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HJKL is a free browser game that teaches Vim through short editing challenges in a real Vim editor. It guides users from practice to independent edits across motions, searches, text objects, and other commands, with no sign-up or stored data. (hjkl.duy.run)
Rustable is an open-source database client written in Rust, available as a desktop app and a browser-based WebAssembly demo. It supports PostgreSQL, SQLite, MySQL, MariaDB, and Redis, with tools for querying, browsing, and editing data. (rustable.app)
OpenAI is scaling Git for its engineering work. The provided comments do not describe the specific changes. (openai.com)
Ruby’s default argument expressions run only when an argument is omitted, so assigning a marker there distinguishes omission from explicit false or nil. This technique lets methods support both reading a value and setting it without a separate sentinel object. (aha.io)
Pratt parsing assigns parsing behavior to tokens based on whether they appear at the start of an expression or after a left-hand expression. Its key insight is organizing parsing around what can appear to a token’s left, rather than around grammar production rules. (vinipsmaker.github.io)
SOML is an open-source configuration format designed to be readable by people. Its repository includes a specification, conformance tests, benchmarks, and comparisons with other formats. (github.com)
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