Since version 2.3 freeciv contains a modpack installer (freeciv-modpack or freeciv-mp-*) for downloading and installing custom content. Users only need to enter a modpack URL, and it will be automatically correctly installed. Users are no more forced to download and copy each file to the correct directory manually, where correct was something that nobody seemed to know what it is for some operating systems.
As of 2.6.x, how to use the tool, and how you as custom modpack author can publish your content are documented in doc/README.modpack_installer in the source distribution. This page mainly has notes on the history.
If you really need to publish a modpack for a pre-2.6 version of Freeciv, you're probably best starting at 2.6 docs and working backward, using files on modpack.freeciv.org as a reference; or you can look at old versions of this page for some more detail.
|Version||Flavours||List capability||Modpack capability||Full docs||Notes|
|2.3||Gtk2||+Freeciv-2.3-modlist||+modpack-090810-2||-|| List URL was hardcoded to server that no longer exists.|
(Copy preserved on files.freeciv.org.)
|2.4||Gtk2||+modlist-011111||+modpack-150611||-|| Added scenario/soundset types.|
List URL and installation prefix changeable at runtime.
Replaced homegrown network access with more reliable Curl library.
|2.5||Gtk2/3, Qt, cli||+Freeciv-2.5-modlist||+Freeciv-2.5-modpack||-|| Added descriptions and subtype.|
Installer started recording history of installed modpacks.
|2.6||Gtk2/3, Qt, cli||See docs||git|| Added dependencies, relative URLs.|
Added "Musicset" type.
|3.0 (TBC)||Gtk2/3/4, Qt, cli||See docs||git||TBC|
Stable versions default to getting modpacks from modpack.freeciv.org, curated by the Freeciv team.
Early development code currently defaults to an experimental area on files.freeciv.org instead. These are maintained by developers as needed for testing, and aren't guaranteed to exist / work at any given time. The "dev" subdirectory is used for the master branch; the "test" directory is used by a stabilising branched version up until data format freeze (see Release Cycle), at which point modpacks move to modpack.freeciv.org.