README

NotepadL++

A fast, native Linux text editor in the spirit of Notepad++ — built in Free Pascal / Lazarus on the ATSynEdit engine. Multi-tab editing, multi-caret, syntax highlighting, powerful find / replace and find-in-files, and built-in JSON/XML/CSV and developer tools. No plugins required.

Status: pre-alpha / under active construction. Not yet ready for daily use. This project is also an experiment: it is being built largely autonomously by an AI coding agent (Claude Code) against a fixed architecture and a test-first acceptance gate. Expect rough edges and incomplete features while Phase 1 lands.

Why this exists

There is no native Notepad++ for Linux, and while NotepadNext is a strong cross-platform reimplementation, it doesn't yet cover the full Notepad++ feature set. NotepadL++ aims at the Notepad++ native experience on Linux (Ubuntu / Linux Mint) — lightweight, instant to launch, keyboard-driven — with the most useful "plugin" functionality baked in out of the box.

Features (Phase 1 scope)

Editing

• Multi-tab interface with session restore (reopens your last files and window state)
• Multi-caret and column / block selection
• Syntax highlighting for a curated set of languages (JSON, XML, HTML, CSS, JavaScript, INI/conf, Shell, Python, C/C++, SQL, YAML, Markdown, Diff, Log, plain text)
• Code folding, bracket matching, line numbers, current-line highlight, word wrap, minimap
• Line operations: duplicate, move, sort, remove duplicates, trim trailing whitespace, case conversion, comment/uncomment, indent/outdent

Files & encoding

• New / Open / Save / Save As / Reload / Recent files
• Encodings: UTF-8 (with and without BOM), UTF-16 LE, UTF-16 BE, Windows-1252 — with byte-exact round-trip saving
• Line endings: detects and converts LF / CRLF / CR independently of encoding

Search

• Find & Replace with match-case, whole-word, regex, wrap-around, count, and mark-all
• Incremental find and go-to-line
• Find in Files: across a directory, with file-mask filters and recursion, regex support, and a navigable results panel (targeting ~90% Notepad++ parity)

Built-in tools (no plugins needed)

• JSON: pretty-print, minify, validate
• XML: pretty-print, validate
• CSV: tabular grid viewer
• Converters: Base64, URL encode/decode, UUID/GUID generation, hash calculator (MD5 / SHA-1 / SHA-256), numeric base conversion

UX

• Light and dark themes
• Status bar with live caret position, selection length, encoding, EOL type, and language — click to change encoding/EOL
• Settings persisted as JSON

Tech stack

Building from source

⚠️ Build instructions are provisional and will be finalized once the toolchain and dependency set are pinned (see DEPENDENCIES.lock).

Prerequisites

• Free Pascal 3.2.2 or newer and Lazarus (the distro packages on Mint/Ubuntu work; fpcupdeluxe is recommended if you need matched FPC/Lazarus versions)
• Dependency packages: ATSynEdit, ATSynEdit_Cmp, ATSynEdit_Ex, EControl, EncConv, BGRABitmap (and ATFlatControls if used)

Build (headless)

git clone https://github.com/<your-user>/notepadlpp.git
cd notepadlpp
# install the dependency packages (via Lazarus OPM or cloned repos), then:
lazbuild NotepadLPP.lpi

Run tests

lazbuild test/TestRunner.lpi && ./test/TestRunner --all --format=plain

Roadmap

Phase 1 (current): the feature set above — a usable, native single-file/multi-tab editor with built-in tools, no plugin system.

Phase 2 and beyond (not yet implemented): a native plugin system / SDK, embedded scripting, macro record & playback, the full lexer set, diff / compare, spell check, function list / code tree, and remote (FTP/SFTP) editing.

Project documentation

The full functional scope, module architecture, and milestone plan live in ARCHITECTURE.md. That document is the authoritative spec; this README is the short version.

Licensing

• NotepadL++ original source: MPL-2.0
• ATSynEdit, ATSynEdit_Cmp, ATSynEdit_Ex, ATFlatControls: MPL-2.0 / LGPL (© Alexey Torgashin)
• EControl syntax engine: open-source-use-only license (see its readme.txt); closed-source use prohibited
• BGRABitmap: modified LGPL (LGPL + static linking exception)

This project is free and open source. Because it bundles EControl, the combined work may be used and redistributed in open-source form only.

Acknowledgements

Built on the excellent ATSynEdit editing engine and EControl syntax parser by Alexey Torgashin, the same foundation that powers CudaText.