altbinaries

altbinaries is a term that generally refers to the alt.binaries mid–level newsgroup hierarchy used on Usenet for the discussion and distribution of binary files. The prefix “alt.” indicates an alternative or non-archived category of newsgroups, and the “binaries” subsumption specifies that its primary purpose is to host or reference data that is not text but encoded for transmission over the Usenet protocol, which historically only supported plain‑text messages.

The alt.binaries hierarchy grew rapidly in the mid‑1990s as the internet expanded and many users sought a method to share large files such as software, images, and videos. Because the UUCP and early Usenet systems could only send ASCII, binary data was encoded using formats such as UUEncode, BinHex, and later Base64, which converted multi‑byte binaries into a printable text stream. The result was that users could post lengthy posts containing large amounts of encoded data, and other users could then retrieve and decode those messages to recover the original binary file.

Throughout its history, altbinaries has been both a platform for legitimate distribution, such as open‑source software releases, and a focus of copyright enforcement actions. As a result, many jurisdictions enacted laws to regulate or prohibit the distribution of copyrighted material via these newsgroups. In response to enforcement pressure, the alt.binaries hierarchy has fragmented into numerous sub‑groups dedicated to specific file genres or legal restrictions.

Today, most altbinaries activity has migrated to modern file‑sharing services and encrypted channels, but the legacy of alt.binaries remains an early example of peer‑to‑peer content distribution, influencing later technologies such as BitTorrent and public‑key based sharing networks. The term altbinaries is occasionally used in technical documentation or community forums to refer specifically to this historical newsgroup ecosystem.