nanobbs, a tiny forums software

nanobbs is a simple and lightweight implementation of a forums software, commonly known as "bulletin board software" or simply "BBS", written in C99 plus POSIX.1-2008 extensions.

Disclaimer

Intentionally, nanobbs does not share some of the philosophical views from the suckless project. However, it still strives towards portability, minimalism, simplicity and efficiency.

Features

No JavaScript.
Typical forums software features: categories, sections, topics and posts.
Create/delete users from the web interface.
Uses libweb, a tiny web framework.
Uses libsodium as its cryptography backend.
Uses SQLite as its database backend.

TLS

In order to maintain simplicity and reduce the risk for security bugs, nanobbs does not implement TLS support. Instead, this should be provided by a reverse proxy, such as caddy.

Root permissions

nanobbs is expected to listen to connections from any port number so that root access is not required. So, in order to avoid the risk for security bugs, please do not run nanobbs as root.

Requirements

A POSIX environment.
libsodium.
SQLite >= 3.0.0 (tentative).
dynstr (provided as a git submodule by libweb).
libweb (provided as a git submodule).
CMake (optional).

Ubuntu / Debian

Mandatory packages

sudo apt install build-essential libsqlite3-dev libsodium-dev

Optional packages

sudo apt install cmake

How to use

Build

Two build environments are provided for nanobbs - feel free to choose any of them:

A configure POSIX shell and mostly POSIX-compliant Makefile.
A CMakeLists.txt.

nanobbs can be built using the standard build process:

Make

$ ./configure
$ make

CMake

$ cmake -B build
$ cmake --build build/

Setting up

nanobbs consumes a path to a directory with the following tree structure:

.
├── nanobbs.db
├── style.css
└── TERMS

Where:

nanobbs.db is the SQLite database.
- Note: nanobbs creates a database with one administrator account, namely admin, if not found, with file mode bits set to 0600.
style.css is the site stylesheet. It can be freely modified.
- Note: nanobbs creates a default stylesheet file, if not found.
TERMS is a text file containing the terms of service for the instance. It can be freely modified.
- Note: nanobbs creates a default terms file, if not found.

Note: nanobbs creates the given directory if it does not exist.

Running

To run nanobbs, simply run the executable with the path to a directory including the files listed above. By default, nanobbs will listen to incoming connections on a random TCP port number. To set a specific port number, use the -p command line option. For example:

nanobbs -p 7822 ~/my-db/

nanobbs requires a temporary directory where files uploaded by users are temporarily stored until moved to the user directory. By default, nanobbs attempts to retrieve the path to the temporary directory by inspecting the TMPDIR environment variable, and falls back to /tmp if undefined.

If a custom temporary directory is required, it can be defined via command line option -t. For example:

nanobbs -t ~/my-tmp -p 7822 ~/my-db

Note: system-level temporary directories such as /tmp might reside on a filesytem different than the one where the database resides. This would force nanobbs to copy the contents from uploaded files from the temporary directory to the database, which might be an expensive operation. Therefore, in order to avoid expensive copies, define a custom temporary directory that resides on the same filesystem.

Why this project?

When looking up a forums software for Speed Dreams, traditional forums software solutions had been considered, such as phpBB, myBB or Discourse, yet raised concerns related to perceived software bloat and/or excessive use of client-side JavaScript.

As of the time of this writing, there was no forums software written in C other than nanobbs, according to Wikipedia. Since slcl, another project with the same philosophy, was motivated by similar goals back then, nanobbs was seen as a good opportunity to show how a solution written in C can be both simple, efficient and safe.

License

nanobbs, a tiny forums software.
Copyright (C) 2025-2026  Xavier Del Campo Romero

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

Also, see LICENSE.