n+ (NPlus)

A lightweight text and code editor for Windows, built in C# / WinForms on top of Scintilla 5 via the Scintilla5.NET wrapper. Inspired by Notepad++, with a focus on session persistence, a built-in macro engine, and live file tailing.

The application targets .NET 8 and ships as a single, self-contained nplus.exe — everything is inside that one file: all managed assemblies, Scintilla's native Scintilla.dll / Lexilla.dll, and a small native launcher. If the .NET 8 Desktop Runtime isn't installed, the launcher offers to download and install it (with your approval) on first run. No installer, no loose DLLs.

Download

Grab the latest nplus.exe from the GitHub Releases page. Just download and run — no installation required. If your PC doesn't have the .NET 8 Desktop Runtime yet, nplus will prompt to install it the first time you launch it.

Features

Editing

• Tabbed multi-document interface with drag-and-drop tab reordering
• Syntax highlighting for C#, C/C++, Java, JavaScript/TypeScript, Python, SQL, Visual Basic, VBScript, PowerShell, PHP, HTML, XML/XAML, JSON, and YAML
• Column / block selection mode (Ctrl+Alt+A) for multi-line edits
• Word wrap, indent guides, whitespace and EOL visualization
• Light and Dark Matrix themes — syntax colors update automatically

Session & Files

• Hot exit / session snapshots — close the app any time; tabs, unsaved changes, window position, and zoom level are restored on next launch
• Recent files menu (last 10)
• Revert to saved to discard unsaved changes
• Read-only Hex view for binary/executable files
• Read-only fallback when a file is locked by another process
• External file change detection — prompted to reload, close, or track renamed files when they are modified, deleted, or renamed by another program
• Tab save-status icons — green dot for saved, orange dot for unsaved changes
• Encoding support — ANSI, UTF-8, UTF-8 BOM, UTF-16 BE BOM, UTF-16 LE BOM, with auto-detect and convert-to options

Macros

• Record keystrokes, navigation, and Find/Replace actions
• Playback once, N times, or to end-of-file (great for log processing)
• Save, load, and edit macros step-by-step — saved macros persist between sessions

Lua Scripting

• Built-in Lua engine (MoonSharp) for programmable, document-aware automation — loops, conditionals, regex, and variables that the record/replay macro engine can't express

• Lua Script Console — a REPL window (Ctrl+Enter to run); globals persist between runs

• Run Lua Script File... — execute a .lua file against the active document

• User scripts live in %AppData%\nplus\scripts (open it from Scripts → Open Scripts Folder)

• Each script runs as a single undo action, so any change is one Ctrl+Z away

• Two globals are exposed to every script:

  • editor.* — read/mutate the active document: GetText / SetText / AppendText, GetSelectedText / ReplaceSelection, GetLine / SetLine / GetLineCount / GotoLine (1-based), caret and selection access, GetFileName / GetTitle
  • app.* — MessageBox, Confirm, Prompt, NewTab, clipboard access, plus print(...) collected into the output

  -- Uppercase the whole document
  editor.SetText(editor.GetText():upper())
  
  -- Prefix every line with its number
  for i = 1, editor.GetLineCount() do
    editor.SetLine(i, i .. ": " .. editor.GetLine(i))
  end

AI Assistant (optional)

• Off by default — nothing runs until you turn it on in AI → Enable AI Assistant and pick a provider in AI → Settings
• Bring your own backend — choose OpenAI (ChatGPT), Azure OpenAI, Claude (Anthropic), Gemini (Google), Ollama (local), or Perplexity; each keeps its own key/model, with a Test Connection button in Settings
• Selection actions — Explain, Improve / Rewrite, or a Custom Prompt on the current selection (or whole document); results open in an editable dialog with Replace Selection / New Tab / Copy
• Agent mode (Action Protocol) — let the AI perform tasks on the active tab. The model replies with a provider-agnostic JSON action plan (replaceDocument, replaceSelection, replaceLine, deleteLines, replace, insert, …); n+ simulates it, shows a diff preview, and applies it only after you confirm — as a single undo step. Available from AI → Run Agent Task on Tab… or the chat panel's Agent mode checkbox. Works on every provider (no native tool-calling required).
• Chat panel — a dockable conversational panel with streaming (token-by-token) responses that can optionally attach the current document as context (Ctrl+Enter to send)
• Keys are stored locally in %AppData%\nplus\ai_settings.json and sent only to the provider you select. No provider SDKs are bundled — it's plain HTTPS, so the single-file build is unaffected.

Find / Replace / Mark / Find in Files

• Normal, Extended (\n, \t), and Regex modes (Ctrl+F, Ctrl+H, Ctrl+B)
• Mark tab highlights all matches and can drop a bookmark on every matching line
• Find in Files (Ctrl+Shift+F) — search across all files in a directory with file-type filters, sub-folder recursion, and hidden-folder inclusion
• Replace in Files — bulk find-and-replace across matching files on disk
• Results appear in a dockable bottom panel; double-click any hit to open the file and jump to the line
• Per-session search history dropdowns (up to 20 entries)

Bookmarks & Line Operations

• Toggle bookmarks (Ctrl+F2), navigate with F2 / Shift+F2
• Copy, cut, or delete all bookmarked lines
• Duplicate, reverse, or randomize line order
• Sort lines: lexicographic, locale, integer, decimal (comma/dot), by length — ascending or descending, with case-insensitive options
• Split lines (Ctrl+I), join lines (Ctrl+J), shift lines up/down (Ctrl+Shift+Up/Down)
• Remove duplicate lines, remove empty lines, insert blank lines above/below
• Blank operations — trim leading/trailing/both whitespace, EOL to space, tabs ↔ spaces conversion

JSON Tools

• Pretty-print / format dense or single-line JSON
• Visual JSON tree explorer in a dockable, resizable side panel

Live File Monitoring (Tail)

• Toggle "Live" mode to auto-reload and auto-scroll on external file changes — tail rolling log files without leaving the editor

Zoom

• F11 / F12 / Ctrl+0 to zoom the entire UI (menu, toolbar, status bar, editor)
• Ctrl+Mouse Wheel to zoom only the current editor tab
• Zoom level persists between sessions

Keyboard Shortcuts

Shortcut	Action
Ctrl+F / Ctrl+H / Ctrl+B	Find / Replace / Mark
F3	Find Next
Ctrl+Shift+F	Find in Files
Ctrl+Alt+A	Toggle column selection mode
Ctrl+F2	Toggle bookmark on current line
F2 / Shift+F2	Next / previous bookmark
Ctrl+J	Join selected lines
Ctrl+Shift+Up/Down	Move line up / down
Ctrl+Shift+P	Playback active macro
F11 / F12 / Ctrl+0	Zoom in / out / reset

Building from Source

Requirements:

• Windows
• .NET 8 SDK
• Visual Studio C++ build tools ("Desktop development with C++") — required to compile the Native AOT launcher.

For day-to-day development of the editor itself (no launcher), just build/run the app project:

dotnet build -c Release

To produce the distributable single-file build, run the build script from the repo root:

.\build.ps1

This writes a single dist\nplus.exe. The build has two parts wired together by the script:

1. The app (nplus.csproj) publishes as a framework-dependent single file. All managed assemblies are bundled by .NET's single-file publish; Scintilla's native Scintilla.dll / Lexilla.dll are carried as embedded resources and extracted to %LOCALAPPDATA%\nplus\native at startup (Scintilla.NET loads them from disk, so they can't live inside the bundle directly).
2. The launcher (Bootstrap\nplus.bootstrap.csproj) is a Native AOT exe — it runs without any installed runtime. It embeds the published app GZip-compressed (shaving ~1.8 MB off the final exe), checks for the .NET 8 Desktop Runtime, downloads + installs it (with the user's consent) if missing, then decompresses + extracts and launches the app.

The result is framework-dependent (the app needs the .NET 8 Desktop Runtime), but the launcher bootstraps that runtime automatically, so the end user only ever needs the one nplus.exe.

Project layout

Path	What it is
nplus.csproj, *.cs	The WinForms editor application.
LuaScripting.cs	The MoonSharp Lua engine: script host, the editor/app APIs, and the Script Console.
AiAssistant.cs	The optional AI assistant: multi-provider HTTP client, settings/result dialogs, and the chat panel.
AiActions.cs	The AI Action Protocol: JSON action parsing, edit simulation, line-diff, and the preview/confirm dialog.
native\win-x64\	Scintilla / Lexilla native DLLs, embedded into the app exe as resources.
Bootstrap\nplus.bootstrap.csproj	The Native AOT launcher (Program.cs).
Bootstrap\RuntimeInstaller.cs	Runtime detection / download / install logic, kept separate and UI-free.
build.ps1	Builds the whole thing into dist\nplus.exe.

Dependencies

• Scintilla5.NET 6.1.2 — editor control (Scintilla 5.5.5 + Lexilla 5.4.3)
• Be.Windows.Forms.HexBox.Net5 1.8.0 — read-only hex view
• MoonSharp 2.0.0 — pure-managed Lua interpreter for the scripting engine (no native deps, so it folds into the single-file build)
• System.Text.Json (built into .NET 8) for JSON formatting / tree view

License

MIT License

Copyright (c) 2026 Mule Skinner

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.