1. Use the vanilla spawn chunks. A 16x16 chunk area is kept loaded at all times while there is at least one player in the overworld around the world spawn. Spawn chunks have some limitations, namely items that require "random ticks" don't get them, so randomish things such as tree and crop growth do not occur. Other than that, spawn chunk's will run most machines
2. Railcraft anchors or dimensional anchors are technically superior to chicken chunks in many ways on servers as the player craftable chunkloaders only load their chunks while the owning player is online.
3. Build craft quarries. Witchery Poppit tables, and Ender IO dimensional transceivers all load chunks. Additionally, Ender IO has implicit chunkloading behaviours: Dimensional Transceivers will load their own chunks, and the entire Ender IO conduit network will also be loaded. You do not need any chunk loaders if you are piping items using transceivers into a Ender IO automated facility, as long as you can make sure that all non ender IO devices there are completely contained in chunks that contain EnderIO bits.
4. Given a loaded chunk, Injecting items into nearby chunks using hoppers will load those chunks. Also buildcraft pipes carrying items work this way. Starting from a known loaded chunk (such as a working quarry), all the items flowing through buildcraft's pipes back to a processing facility will load all chunks along the way. Careful placement of machines within chunks that are intersected by BC pipes will keep those machines operating.
Option 2 is the friendliest for server play. All the other options will strain the server TPS while the player is not online, potentially negatively effecting other players. This is why, especially on servers, chunkloading should be done with railcract personal anchors (configured to be fuel free) or world anchors - configured to consume a stack of fuel over a few hours, and with automatic input disabled. This setup limits the ability of players to use chunkloaders to negatively effect server performance long after they are done playing. How the impact of the other methods is controlled is up to the server operator.
Please don't be a dick and do any of those things on a public server.