Celes

A markup language designed for archiving. Explicit syntax. Built to last.

---

<!Celes-0.1.5>
<title>{Hello World}
<background>{#0f0f0f}
<header -size=1>{Welcome to Celes}
<line>{This is <bold>{bold}, <mark>{highlighted}, and <coloredtext -color=#D4622A>{colored} text.}
<list -bullet=circle>{Plain text — readable forever}
<list -bullet=circle>{Strict parser — errors are never silent}
<list -bullet=circle>{Version-stamped — every file knows its spec}
<line>{<button -body=Get Started>{https://celes.is-best.net}}

---

Why Celes?

Most document formats are designed to look good today. Celes is designed to still be readable in 50 years.

Word documents corrupt. Markdown parsers disagree on spec. HTML rots. PDFs are opaque binaries. None of them were built with long-term archiving as the primary goal.

Celes is plain UTF-8 text with named tags and explicit attributes. Every document declares its version at the top. A future parser — or a human with no tooling — can read it without guessing.

; Markdown — ambiguous
**bold** or __bold__?    * list or *italic*?

; Celes — one way to do everything
<bold>{bold}             <list -bullet=circle>{item}

---

Installation

pip install celes

Requires Python 3.8+. No external dependencies.

---

CLI

# Parse Celes → HTML
py -m celes parse doc.celes doc.html

# Validate a file
py -m celes validate doc.celes

# Convert Markdown → Celes
py -m celes md README.md README.celes

# Convert Celes → Markdown
py -m celes tomd doc.celes doc.md

---

Python API

from celes import parse_celes, validate_celes, convert_md_to_celes, convert_celes_to_md

# Parse to HTML
html = parse_celes(source)

# Validate — returns (is_valid, list of errors)
is_valid, errors = validate_celes(source)
for e in errors:
    print(e)  # "  ✗ Line 3: <header> is missing required -size attribute"

# Convert
celes_source = convert_md_to_celes(markdown_source)
markdown_source = convert_celes_to_md(celes_source)

---

Syntax

Every Celes file starts with a version declaration:

<!Celes-0.1.5>

Comments use a semicolon prefix:

; This is a comment

Document & Metadata

Tag	Description
<title>{text}	Browser/tab title
<author>{name}	Author metadata (not rendered)
<date>{dd/mm/yyyy}	Date metadata (not rendered)
<background>{color}	Page background — named color or hex e.g. #1a1a2e (new in 0.1.5)

Block Tags

Tag	Description
<header -size=1>{text}	Heading, size 1–6
<section>{name}	Named section divider with horizontal rules
<line>{text}	Paragraph
<line -align=center>{text}	Aligned paragraph (left, center, right)
<blockquote>{text}	Blockquote
<codeblock>{code}	Multi-line code block (raw — nothing inside is parsed)
<image>{path/url}	Image
<linkimage -image=path.png>{url}	Clickable image
<video>{url}	HTML5 video player (new in 0.1.5)
<audio>{url}	HTML5 audio player (new in 0.1.5)

Lists

Tag	Description
<list -bullet=circle>{text}	Bullet list item
<list -bullet=number>{text}	Numbered list item
<sublist -bullet=circle>{text}	Nested item (level 2)
<subsublist -bullet=circle>{text}	Deeply nested item (level 3)

Tables

<table>{Name, Age, City}
<item>{Alice, 30, New York}
<item>{Bob, 25, London}

Commas are reserved as column separators — cell values cannot contain commas.

Self-Closing Tags

Tag	Description
<newline>	Line break
<pagebreak>	Page break
<insertspace>	Extra spacing / horizontal rule

Inline Tags

Tag	Description
<bold>{text}	Bold
<italic>{text}	Italic
<bold+italic>{text}	Bold and italic
<underline>{text}	Underline
<strike>{text}	Strikethrough
<super>{text}	Superscript
<sub>{text}	Subscript
<mark>{text}	Highlighted text
<code>{text}	Inline code
<coloredtext -color=value>{text}	Colored text — named color or hex (new in 0.1.5)
<link -body=display text>{url}	Hyperlink
<button -body=label>{url}	Clickable button
<checkmark -check>{text}	Checked item (inside <list>)
<checkmark -uncheck>{text}	Unchecked item (inside <list>)
<nestquote>{text}	Nested blockquote (inside <blockquote>)
<empty>{raw text}	Raw text — nothing inside is parsed

Video & Audio Attributes

Tag	Attribute	Description
<video>	-loop	Loops on end
<video>	-autoplay	Plays on load (pair with -mute for browser compatibility)
<video>	-mute	Muted playback
<audio>	-loop	Loops on end
<audio>	-autoplay	Plays on load

---

Full Example

<!Celes-0.1.5>
<title>{My Page}
<author>{Sourasish Das}
<date>{13/03/2025}
<background>{#0f0f0f}

<section>{Introduction}
<header -size=1>{Hello, Celes 0.1.5!}
<line>{This is <bold>{bold}, <italic>{italic}, <mark>{highlighted}, and <coloredtext -color=#D4622A>{colored} text.}
<line>{Water is H<sub>{2}O. Visit <link -body=example>{https://example.com}.}
<line>{<button -body=Click Me>{https://example.com}}
<newline>

<section>{Lists}
<list -bullet=circle>{Fruits}
<sublist -bullet=circle>{Citrus}
<subsublist -bullet=circle>{Lemon}
<subsublist -bullet=circle>{Lime}
<list -bullet=number>{Step one}
<list -bullet=number>{Step two}
<newline>

<section>{Data}
<table>{Name, Age, City}
<item>{Alice, 30, New York}
<item>{Bob, 25, London}
<newline>
<codeblock>{print("Hello, World!")}
<blockquote>{A quote. <nestquote>{A nested quote.}}

<section>{Media}
<video -loop -mute>{assets/demo.mp4}
<audio>{podcast-episode-1.mp3}
<insertspace>
<line -align=center>{Made with <bold>{Celes} 0.1.5}

---

Tools

🖊 WYSIWYG Editor

A standalone browser-based editor — no install needed. Word-like toolbar, live Celes output panel, and a raw Celes playground. Try it online or open celes-editor.html in any browser.

💻 Desktop App

A native Windows application (Celes.exe) wrapping the editor with native Open / Save / Export HTML file dialogs.

• Ctrl+S — Save
• Ctrl+Shift+S — Save As
• Ctrl+O — Open .celes file
• Ctrl+Shift+E — Export to HTML

🧩 VS Code Extension

Syntax highlighting, snippets for every tag, live validation with error squiggles, and a live HTML preview panel.

🌐 Browser Extension

Automatically renders .celes files when opened in Chrome or Edge. Supports file:// and http:// URLs.

---

Project Structure

Celes/
├── celes/                  # Python package (pip install celes)
│   ├── parser.py           # Celes → HTML
│   ├── validator.py        # Strict validator with line-number errors
│   ├── md_to_celes.py      # Markdown → Celes
│   └── celes_to_md.py      # Celes → Markdown
├── celes-vscode/           # VS Code extension
├── celes-browser/          # Chrome / Edge extension
├── celes-desktop/          # PyInstaller desktop app
├── celes-editor.html       # Standalone WYSIWYG editor
├── Celes-0.1.5-Spec.md     # Full language specification
└── README.md

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Changelog

0.1.5

• Added <video> — HTML5 video player with -loop, -autoplay, -mute
• Added <audio> — HTML5 audio player with -loop, -autoplay
• Added <background> — document-level page background color
• Added <coloredtext -color=value> — inline colored text
• Parser: <coloredtext> without -color is a parse error
• Parser: duplicate <background> warns and uses first value
• Parser: <video>/<audio> used inline is a parse error
• Parser: -autoplay without -mute on <video> warns
• Fixed multiline <codeblock> parsing in all JS parsers

0.1.4

• Added <super>, <sub>, <mark>, <button>, <subsublist>, <section>, <author>, <date>
• Desktop app (Celes.exe) with native file dialogs
• VS Code extension published to marketplace
• Browser extension for Chrome and Edge

0.1.1 – 0.1.3

• License updated to SOCL 1.0
• Minor parser and packaging fixes

0.1.0

• Initial release

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License

Server-Lab Open-Control License (SOCL) 1.0 — Copyright © 2025 Sourasish Das.

Feedback

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