How to open .BOO files on Mac

To open .BOO files on Mac, open the .BOO file in a plain-text editor (TextEdit in plain-text mode or a code editor) to determine whether it is Kermit BOO encoded text or Boo source code.

Step-by-step instructions

  1. Open the .BOO file in a plain-text editor (TextEdit in plain-text mode or a code editor) to determine whether it is Kermit BOO encoded text or Boo source code.
  2. If it is Kermit BOO encoding, decode it using a Kermit/BOO-capable tool on a desktop system (you may need to transfer the file to a system where your Kermit tools are installed).
  3. If it is Boo language source (.boo), open it in a code editor as a normal text file.

Alternative methods

  • Open .BOO in a browser-based viewer if desktop apps fail.
  • Try opening .BOO on Mac with a secondary app to rule out app-specific issues.
  • Convert .BOO only with trusted tools when direct opening is not possible.

Common issues

The .BOO file opens as gibberish or won’t “run”

Kermit BOO files are meant to be decoded back into the original binary; viewing them directly shows encoded text, not the usable program.

  1. Open the file in a text editor and confirm it is printable ASCII and appears to be a Kermit BOO encoding (often with an initial line indicating the original filename).
  2. Use a Kermit/BOO decoding tool to convert it back into the original file, then open/run the restored file with the correct program for that file type.

An archive tool says the .BOO file is not a supported archive

.BOO is not universally an “archive”; it may be Kermit BOO-encoded binary or a different .boo usage such as source code.

  1. Try opening it as plain text to determine whether it is Kermit BOO encoded text or Boo source code.
  2. If you specifically expected a BOO compressed archive, try ZipZag on Windows (commonly referenced for BOO archives); otherwise use Kermit BOO decoding instead.

Decoded output is corrupted or the filename is wrong

BOO decoding depends on intact text content; line-ending changes, truncation, or copy/paste transfers can break the encoding. The original filename is typically stored in the first line of the BOO file.

  1. Re-download or re-transfer the .BOO file using a method that preserves the exact text (avoid copy/paste; use file transfer).
  2. Ensure the decoder is treating the input as text and that the first line (original filename line) is intact before decoding again.

Confusion with Boo programming language files (*.boo)

Some systems associate .boo with the Boo programming language (a text source file) and may not recognize it as Kermit BOO encoding.

  1. Open the file in a text editor: Boo source looks like normal code, while Kermit BOO is an encoding block intended for decoding to a binary.
  2. If it is code, keep it as text and use developer tooling; if it is Kermit BOO, use a BOO decoder workflow instead of code tools.

Security note

Kermit BOO files are commonly used to distribute binary programs; after decoding, the output may be an executable. Treat the decoded file as untrusted until you know its origin and purpose.

Back to .BOO extension page