I'll explain what the mods on civcraft.vg are. I've just gotten back into the world and have met up with some guys in Carbon, it's a fairly well developed city which is well placed for naval transport to other places, at least I can get there from my mountain home in a short time, It's connected to the main transport hub which links up all the larger cities near the center, the CIC network is currently undergoing upgrades in a few test areas for 'supercart' capability. Basically stacks of minecarts travel better or something , I'm not sure.
The world itself extends 15,000 blocks from spawn in each direction and most cities are clustered a few thousand blocks from 0,0, the extensive rail network allows fast travel to key points, while going from -15000 to + 15,000 would take an hour, no large cities are quite that far apart (maybe some secret ones are). The nether currently is disabled in order to facilitate difficult and long travel, also for economic and security reasons. However the admin is currently working on reimplementing the nether in a manner that would suit the rest of the world's enviroment. Large nether biome areas do currently exist in order to get blocks, but being in the overworld you don't get nether mob spawns, these areas are rare too. However zombie pigmen do spawn from portals making them a good source of gold.
Here's a link to a description of the mods:
http://www.reddit.com/r/Civcraft/comments/1emr0o/welcome_to_civcraft_20_a_basic_guide_to_the_mods/ Thus far the only mods I've seen in action are:
Realistic biomes; this significantly slows down plant growth, and requires using suitable biomes if you want things to grow with any speed.
For instance in a forest biome a tree will grow in 6 hours, elsewhere it will take 2 days (the chunk has to be loaded for growth to occur), important to note that no plants will grow in ocean biomes( my house is in an ocean
). Crops grow significantly faster when theres clay under the soil, also sunlight is required, or being only a single block away from glowstone.
Citadel: Blocks can be reinforced through the use of a stone, iron bar, or diamond. A reinforced block requires you to break it 25, 250 or 1800 times before it will actually break, the peoson who has reinforced the block can easily remove the protection, or give access to another person or group. Reinforced chests, doors, etc will be locked, but your stuff can be stolen by a determined enough attacker.
Jukealert: Uses juke boxes to monitor areas, hide them around and you can spy on who is griefing your stuff.
Prison pearl: Killing another player with a Ender pearl in your hotbar will imprison them in the end. You must 'feed' the pearl 2 coal a day to retail the imprisonment. Cities build well protected reenforced vaults for keeping high security prisoners in. Generally Cities have laws which are enforced with short 'pearling' sentences. Players can offer a bounty on a pearl containing other players, generally you'll need to post proof of their transgression on reddit before someone will accept.
And factory mod: Allows the production of "factories" which can construct large stacks of Items for significant savings on their usual cost, XP can only be produced through bottles, mining, killing mobs, harvesting etc no longer provides any XP. But factories also provide another way of enchanting items.
Theres a few others on that page which I haven't really encountered or noticed.
Oh and one last thing, the Government of Carbon wishes to inform all migrants and travellers that the production or consumption of Bread within the City limits is prohibited and serious infractions will be enforced with pearling, Have a nice day.