Artemis vs Ashley: (Don't) Fight!

Ashley/Artemis Comparison (WIP)

Disclaimer: i'm one of the maintainers of artemis-odb, might be a bit biased.

Performance For a basic game with a couple hundred entities and limited composition changes, it probably doesn't matter which framework you pick. A minimal artemis-odb setup is basically a slightly faster Ashley with dependency injection.

Artemis-odb benchmarks better towards the extremes; loads of transitions, particles, slow platforms etc. Enabling the more advanced features, artemis-odb becomes both faster and a bigger gun to shoot yourself in the foot with. If you are confident around Java and Gradle (or Maven) doesn't scare you, this shouldn't be too much of an issue. If you are new to Java, ECS or Gradle - Ashley might be a better choice.

Community health: Both frameworks see a fair amount of use and are similarly maintained. Ashley has better support on the libGDX Discord.

Maintenance: If all developers of Ashley get hit by a bus a fork wouldn't be too hard to maintain. If all the developers of artemis-odb get hit by a bus it'll take a bit more effort.

libGDX support: Ashley depends on libGDX for some utility classes, artemis-odb supports libGDX but does not have a dependency on any artifacts.

Prototyping: Artemis-odb has some nice features to prototype really quickly;

• Dependency injection saves a lot of typing.
• Fluid entities make entities really easy to edit without having to use component mappers in the first place e.pos(10,10).anim("chicken").deleteFromWorld() (at the cost of some performance).
• Save and load: single entities or full levels, Prefabs for parameterized loading. Great when coupled with some basic editor tooling.

tldr; Ashley is at its core a capable ECS with no frills, and part of the core libGDX package. Artemis-odb is performance oriented, feature rich and extensible with several pre-made plugins, requiring a bit more skill to set up.

Core features

Core features	Ashley	Artemis	Notes
Version	1.7.3 (2017)	2.2.0 (2019)
Part of libGDX	Yes	No
libGDX dependency	Yes	No	Ashley depends on libGDX for collections and some other bits. odb has optional modules designed for libGDX, like libGDX-json.
Setup	Easy	Medium/Experienced**	** quickstart available
Dependency injection	No	Built in
Reflection on HTML5	libGDX*	Yes	odb injects component mappers and systems automatically.
Maximum components	?	?
Maximum systems	?	?
Multiple engine instances	yes	yes
Entity change listeners	yes	yes
Custom update cycle	extend Engine?	via interface	See InvocationStrategy
Multithreaded access to world	?	not out of the box
Plugin framework	No	Built in
Entity exposed	as object	as object or int

Drop-in plugins

Plugins / Addons	Ashley	Artemis	Details
Operations-DSL (change entity over time, tweening)	-	Yes	artemis-odb-orion, contrib-plugin-operations
Events	-	Yes	GMWolf/artemis-odb-eeel, contrib-eventbus
Fluid entities (convenience fluent API for altering entities)	-	Yes
Kotlin DSL	Yes	-	ktx-ashley
Full/partial World serialization (Json)	-	Yes	3 lines of code to/from json save
Full/partial World serialization (binary/Kryo)	-	Yes	2 lines of code to/from binary save
System profiler (time-per-system)	-	Yes	contrib-plugin-profiler