recs-1.0.0 has been yanked.
Rustic Entity-Component System 
Simple entity-component system in pure Rust. Type reflection - no macros!
Install
Using Cargo, just add the following to your Cargo.toml:
[dependencies.recs]
git = "https://github.com/andybarron/rustic-ecs"
(Coming soon to crates.io!)
Example
extern crate recs;
use recs::{Ecs, EntityId};
#[derive(Clone, PartialEq)]
struct Age{years: u32}
#[derive(Clone, PartialEq)]
struct Brain{iq: i32}
fn main() {
// Create an ECS instance
let mut ecs: Ecs = Ecs::new();
// Add entity to the system
let me: EntityId = ecs.create_entity();
// Attach component to the entity
ecs.set(me, &Age{years: 22});
// Get attached component data from entity
let older = ecs.get::<Age>(me).unwrap().years + 1;
// Modify an entity's component
ecs.set(me, &Age{years: older});
// It works!
assert!(ecs.get::<Age>(me) == Some(Age{years: 23}));
assert!(ecs.get::<Brain>(me) == None); // Aw man...
}