In 2050 AD, the European Space Agency on Terra launched an extremely long-range colonial expedition. It consisted of three specially created vessels, the Voyageur, C-Jammer and Marinus van der Lubbe. These colony ships would found the various Human nations of 'the Islands', deep within the Great Rift.
Languages
Each of the three original colony missions had a primary national identity, and aboard each there was a primary language:
C-Jammer: English
van der Lubbe: German
Voyageur: French
Other languages were spoken by the colonists, but these gradually faded away after contributing a few words and figures of speech to the main language of the ship.
The colonies established were largely isolated for a thousand years, with only occasional visits from sublight vessels. The local language of each world therefore drifted considerably, though common recorded media slowed the process. The version of French spoken on Amondiage is therefore somewhat different from that of Sansterre, though the difference is one of dialect rather than a different language entirely.
Since Anglic is largely derived from English, with some French influence, the Galanglic-speaking Imperials who first visited the Islands had little difficulty with translation. However, the majority of Islanders see no real need to learn Galanglic. Only those dealing regularly with outsiders are likely to do so.
Terminology in the long-isolated Islands is often subtly different from the standard Imperial usage. For example, the Islanders have no use of the term 'system defence boat' and overall make no real distinction between Jump-capable and non-Jump-capable vessels. Centuries of sublight interstellar flight have resulted in a different mindset that the more recent availability of Jump drive hasn't considerably changed.
Culture
Here too the long isolation has led to distinctions from Imperial society. The blanket opposition to Psionics doesn't exist in the Islands (though Psionic individuals are rare), and the prohibitions on weaponry attached to robots are also not in evidence.
Military
Naval assets in the Islands are overall smaller than in the Imperium. One consequence of this is that fighters are a more credible threat to so-called "capital ships".
New Colchis System
All navies in the Islands make use of vessels which are larger than fighters but not significant combatants by outsider standards. These range from overgrown fighters through to about 300 tons displacement. The 100-ton 'small craft' breakpoint used in the Imperium is esentially meaningless to the Islands. Instead, local craft are designated according to their role.
FAC, Fast Attack Craft: Used for any highly manoeuvrable craft, whatever the armament
PC, Patrol Craft: Slower vessels, usually with greater endurance
SC, Support Craft: A catchall term for small combat-capable vessels that fit neither of the other designations.
Travel
Within the Islands, there are obvious Jump-2 trade runs. It is possible to go from Serendip Belt to New Colchis via Topas, Berlichingen, Neubayern, Sturgeon's Law, Elysee and Herzenslust. This route is generally termed the 'Crescent Run'.
Another transit, known as 'The Loop', runs from Neubayern via Schlesien Belt, St Genevieve, Sansterre, St Denis, Amondiage, Acadie and Colchis to New Home. It is possible to loop back to Neubayern via Sturgeon’s Law, or to cross from the Crescent to the Loop.
The Trans-Rift Route
The typical Great Rift crossing from the main body of Imperial territory to those regions 'behind the claw' is via the Islands Cluster:
Authorities at Filentred make a stringent drive check; upon passing, a vessel is allowed to Jump into the Rift, to Riftspan Station.
From Riftspan Station a jump is made to Amondiage, another Jump-4 (or 2-Jump-2) away.
Most vessels then proceed via New Home, Elysee and then Serendip Belt. Gloire is an alternate destination but this is discouraged by the government of Serendip Belt.
Another four-parsec transit takes the vessel to Zuflucht, on the very outer edge of the Islands.
Zuflucht is the exit (or entry) point for virtually all trans-Rift traffic.
Transit on from Zuflucht requires another deep-space refuelling operation, this time at a purpose-built deep-space installation named Chandler Station.