FidoNet

A worldwide amateur message and file exchange network that moved mail between bulletin board systems long before the modern web flattened everything into tabs.

When this site says “FidoNet,” it means the wider network culture around nodes, routing, echomail, netmail, packets, and the software built to read and move those messages around.

FTN

Short for Fido Technology Network or Fido-style network, depending on who is talking and how old the doc is.

It is the broader technical family around Fido-style addressing, packets, message movement, and compatible software, including systems outside the original FidoNet proper.

Echomail

Public distributed discussion areas replicated across many systems.

Think forum topics that were moved around as message bundles between nodes, except slower, weirder, and often more durable than half the social web.

Netmail

Point-to-point private mail between addresses on the network.

Netmail is not a public echo. It is directed mail addressed to a specific FTN node or user and usually treated more like delivery than discussion.

Message area

A named collection of related messages.

In practice, a message area is the thing a user browses as a topic, conference, or echo. The storage under it can vary by message-base format.

Message base

The on-disk storage format that holds message data and indexes.

JAM, Squish, Hudson, and `*.MSG` are all message-base approaches. Same broad purpose, different file structures and software expectations.

Packet

A file bundle used to move mail between systems.

Packets are the handoff format for transporting messages from one node to another. They are about movement between systems, not about how a local reader stores mail once it lands.

Tosser

Software that sorts incoming mail into the right areas and prepares outgoing mail for export.

If the packet is the bag of mail, the tosser is the thing that empties it, files it properly, and assembles the next bag to send onward.

Scanner

Software that scans message areas for outgoing traffic that needs exporting.

Some docs talk about tossing and scanning together because one is about incoming organization and the other is about outgoing collection.

JAM

A message-base format designed for speed, indexing, and broad software support.

JAM became widely supported in FTN software and is one of the obvious formats to present as a downloadable archive bundle on this site.

Squish

A message-base format associated with the Squish message processor and related FTN tooling.

Squish is both a familiar format name and part of the software culture around moving and storing echomail and netmail.

Hudson

An older message-base style strongly associated with QuickBBS and related systems.

When people mention Hudson here, they mean the classic board-era storage layout rather than a shiny brand with a trademark department.

*.MSG

The simple one-message-per-file storage style used by many Fido-style systems.

It is exactly what it sounds like: lots of separate message files. Crude by later standards, but historically important and very recognisable.