Simple Framework (LuaU)

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Shared = require(ReplicatedStorage:WaitForChild("Shared"))
local Services = script:WaitForChild("Services")
-- // A "Service" simply returns to a server-sided script.

local RequiredServices = {}

for _,Service in ipairs(Services:GetDescendants()) do
    -- // We use ipairs because GetChildren() returns an array, which has Index = Value pairs. ipairs.
    if Service.ClassName ~= "ModuleScript" then
        continue
        -- // Continue forces a loop to it's next iteration, it is an alternative to;
        --[[
            if Condition then
                -- Code
            end

            -- // This is called indentation reduction.
        ]]
    end

    RequiredServices[Service.Name] = require(Service)
    -- // ex; ServiceTemplate = {Init = function(), Start = function()}
end
-- // The reason we run this loop is because we must iterate through all the services twice.
-- // Once to run all Init() functions, and once those are done, again to run Start() functions.
-- // The point of Init() functions is to setup things that will be used in other scripts, in the other scripts Start().

_G.GetService = function(Service)
    for Name, Module in RequiredServices do
        if Name == Service then
            return Module
        end
    end

    error("Could not find service :"..Service)
end
for Side, Table in Shared do
    if Side == "Client" then
        continue
    end

    for Name, Function in Table do
        _G[Name] = Function
    end
end

for Name, Service in RequiredServices do
    if Service.Init then
        Service.Init()
    end
end

for _,Service in RequiredServices do
    if Service.Start then
        Service.Start()
    end
end

for _,Service in RequiredServices do
    if Service.Secondary then
        Service.Secondary()
    end
end