macOS
Homebrewverified · 100%
brew install base91local Homebrew formula metadata
MacPortsverified · 94%
sudo port install base91MacPorts ports tree · mail/base91/Portfile · source: api.github.com
brew
Install base91 with Homebrew, MacPorts, Nix
Utility to encode and decode base91 files. Version 0.6.0 via Homebrew; verified from local package data.
install
Additional install commands
Linux
Nixverified · 92%
nix profile install nixpkgs#base91nixpkgs package indexes · pkgs/by-name/ba/base91/package.nix · source: api.github.com
overview
Package summary
Utility to encode and decode base91 files
Project links
Commands and aliases
- b91dec
- b91enc
- base91
history
Project history and usage
basE91 is a binary-to-text encoding method and command-line tool that encodes binary data as ASCII characters with less overhead than Base64 for many inputs.
Project history
The SourceForge project page describes basE91 as an advanced method for encoding binary data as ASCII characters, similar to uuencode or Base64 but more efficient. It reports overhead of at most 23 percent and as low as 14 percent depending on input.
The SourceForge files page identifies the latest 0.6.0 Java archive release in November 2006, and the project page shows project activity dating to October 2006. The project's official website remains base91.sourceforge.net.
Adoption history
basE91 remains niche, but the input package metadata lists Homebrew, MacPorts, and Nix packaging, and the SourceForge project records tens of thousands of file downloads over its lifetime. Its adoption is mostly among developers who specifically need denser ASCII armoring than Base64 rather than users of general-purpose OS tooling.
The project page classifies it under data formats, terminals, email, algorithms, and internet topics, reflecting the encoding's intended transport and storage use cases.
How it is used
The packaged CLI exposes base91 plus b91enc and b91dec executables according to the Homebrew input metadata. It is used as an encoder/decoder filter for files or streams where ASCII-safe text output is required.
There is no documented configuration file or credentials store; the tool is a stateless encoder/decoder.
Why package nerds care
basE91 is significant as one of the better-known post-Base64 ASCII-armoring experiments. It trades simplicity and universal support for denser output, which makes it a useful reference point in discussions of binary-to-text encoding efficiency.
Its package-manager presence is also a classic long-tail case: a 2006 SourceForge utility still appears in modern package indexes because encoding tools age slowly when their formats are stable.
Timeline
- 2006: SourceForge project activity and project metadata date basE91 to October 2006.
- 2006: Latest SourceForge release path records version 0.6.0 in November 2006.
- 2020s: Input package metadata shows basE91 available through Homebrew, MacPorts, and Nix.
Related projects
- Base64 and uuencode are the official comparison points named by the SourceForge description.
- Other ASCII-armoring and binary-to-text encodings, including Ascii85/Base85, are conceptually adjacent even though they are separate formats.
- SourceForge hosts the original project site and release files for basE91.
Sources
security posture
Risk level: green
narrow executable package without higher-risk signals.
Risk classifier
green risk · low confidence · appliance
Why
- narrow executable package without higher-risk signals
Signals
- metadata:no-higher-risk-signals
Install behavior
- No Homebrew post-install hook is recorded in formula metadata.
- Homebrew bottle metadata is available for 13 platform targets.
Recommended review
Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.
executables
Installed executables
| Command | Kind | Exposure | Note |
|---|---|---|---|
b91dec | cli | global executable | |
b91enc | cli | global executable | |
base91 | cli | global executable |
freshness
Version and freshness
These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.
page generated2026-07-08
manager version0.6.0
manager updated
local dataok
upstreamnot checked
latest detectednot detected
https://base91.sourceforge.net/
- infoNo package-manager update timestamp was available.low confidence
- infoRelease/tag comparison is only available for GitHub repositories.https://base91.sourceforge.net/none confidence
install metadata
Package metadata
| Package key | brew:base91 |
|---|---|
| Version | 0.6.0 |
| Package manager | Homebrew |
| Package manager page | https://formulae.brew.sh/formula/base91 |
| Homepage | https://base91.sourceforge.net/ |
| Upstream docs | https://base91.sourceforge.net/ |
| License | BSD-3-Clause |
| Source archive | https://downloads.sourceforge.net/project/base91/basE91/0.6.0/base91-0.6.0.tar.gz |
| Bottle | available (on arm64_big_sur, arm64_linux, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, big_sur, catalina, monterey, sonoma, ventura, x86_64_linux) |
| Homebrew post-install | not defined |
| Service | none declared |
registry facts
Source database details
| Source Database | Homebrew formula API |
|---|---|
| Tap | homebrew/core |
| Full Name | base91 |
| Version Scheme | 0 |
| Revision | 0 |
| Bottle Stable Root URL | https://ghcr.io/v2/homebrew/core |
| Deprecated | no |
| Disabled | no |
| Keg Only | no |
| URL Keys |
|
source database matches
Other package-manager records
Matches are pulled from external package-manager indexes and kept separate from local Automic Vault package links.
Nix95%
base91
nix profile install nixpkgs#base91- normalized package name match
- Matched by: Base91
MacPorts95%
base91
sudo port install base91- normalized package name match
- Matched by: Base91
source trail
Generated from repository data
This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.
Combined YAML source
View the package source record on GitHub.
Used sources
- Geiger risk classifier
- Nucleus package database
- av.db category and tag curation
- cross-ecosystem install command graph
- curated package history
- external package-manager database matches
- package relationship graph
- package version freshness
- package-page enrichment