Pros of Flowable Engine

• Lighter weight and more modular architecture
• Better performance for high-volume scenarios
• More flexible and extensible API

Cons of Flowable Engine

• Smaller community and ecosystem compared to Camunda
• Less comprehensive documentation and tutorials
• Fewer out-of-the-box integrations with third-party tools

Code Comparison

Flowable Engine process definition:

<process id="myProcess">
  <startEvent id="start" />
  <userTask id="userTask" name="User Task" />
  <endEvent id="end" />
  <sequenceFlow sourceRef="start" targetRef="userTask" />
  <sequenceFlow sourceRef="userTask" targetRef="end" />
</process>

Camunda process definition:

<bpmn:process id="myProcess" isExecutable="true">
  <bpmn:startEvent id="StartEvent_1" />
  <bpmn:task id="Task_1" name="User Task" />
  <bpmn:endEvent id="EndEvent_1" />
  <bpmn:sequenceFlow id="SequenceFlow_1" sourceRef="StartEvent_1" targetRef="Task_1" />
  <bpmn:sequenceFlow id="SequenceFlow_2" sourceRef="Task_1" targetRef="EndEvent_1" />
</bpmn:process>

Both engines use similar BPMN-based XML for process definitions, with minor differences in namespace and element naming conventions. Flowable tends to have slightly more concise syntax, while Camunda follows BPMN 2.0 specifications more strictly.

Pros of Activiti

• Lighter weight and more flexible for embedding in Java applications
• Stronger focus on core BPMN execution engine
• More active community contributions and frequent releases

Cons of Activiti

• Less comprehensive enterprise features out-of-the-box
• Smaller ecosystem of tools and integrations
• Less extensive documentation and learning resources

Code Comparison

Activiti process definition:

<process id="myProcess">
  <startEvent id="start" />
  <userTask id="userTask" name="User Task" />
  <endEvent id="end" />
  <sequenceFlow sourceRef="start" targetRef="userTask" />
  <sequenceFlow sourceRef="userTask" targetRef="end" />
</process>

Camunda process definition:

<bpmn:process id="myProcess" isExecutable="true">
  <bpmn:startEvent id="start" />
  <bpmn:userTask id="userTask" name="User Task" />
  <bpmn:endEvent id="end" />
  <bpmn:sequenceFlow sourceRef="start" targetRef="userTask" />
  <bpmn:sequenceFlow sourceRef="userTask" targetRef="end" />
</bpmn:process>

Both Activiti and Camunda use similar BPMN 2.0 XML syntax for process definitions. The main difference is that Camunda uses the bpmn: namespace prefix, while Activiti doesn't. Camunda also includes the isExecutable="true" attribute on the process element by default.

Pros of camunda

• More comprehensive and feature-rich workflow engine
• Supports both BPMN and DMN standards
• Offers a wider range of deployment options (on-premise, cloud, hybrid)

Cons of camunda

• Steeper learning curve due to more complex architecture
• Requires more resources to run and maintain
• May be overkill for simpler workflow needs

Code comparison

camunda:

@Deployment(resources = "process.bpmn")
public void testProcess() {
  runtimeService.startProcessInstanceByKey("myProcess");
  Task task = taskService.createTaskQuery().singleResult();
  assertEquals("My Task", task.getName());
}

camunda:

@Test
public void testProcess() {
  ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("myProcess");
  assertThat(processInstance).isNotNull();
  assertThat(taskService.createTaskQuery().processInstanceId(processInstance.getId()).count()).isEqualTo(1);
}

Summary

Both repositories are related to the Camunda workflow engine, but they serve different purposes. The camunda repository is the main project, offering a full-featured workflow and decision automation platform. It provides a robust set of tools for modeling, executing, and managing business processes. On the other hand, the camunda repository's purpose is not clear from the given information, as it appears to be a duplicate or potentially a different project with the same name. Without more context, it's difficult to make a meaningful comparison between the two repositories.

Pros of Airflow

• More extensive ecosystem with a larger community and wider range of integrations
• Better suited for data pipeline orchestration and ETL workflows
• Offers a more flexible and pythonic approach to workflow definition

Cons of Airflow

• Steeper learning curve, especially for non-Python users
• Can be more resource-intensive and complex to set up and maintain
• Less focus on business process modeling compared to Camunda

Code Comparison

Airflow DAG definition:

from airflow import DAG
from airflow.operators.python_operator import PythonOperator
from datetime import datetime

def my_task():
    print("Hello from Airflow!")

dag = DAG('simple_dag', start_date=datetime(2023, 1, 1))
task = PythonOperator(task_id='my_task', python_callable=my_task, dag=dag)

Camunda BPMN process definition:

<bpmn:process id="Process_1" isExecutable="true">
  <bpmn:startEvent id="StartEvent_1" />
  <bpmn:task id="Task_1" name="My Task">
    <bpmn:script>print("Hello from Camunda!");</bpmn:script>
  </bpmn:task>
  <bpmn:endEvent id="EndEvent_1" />
  <bpmn:sequenceFlow id="Flow_1" sourceRef="StartEvent_1" targetRef="Task_1" />
  <bpmn:sequenceFlow id="Flow_2" sourceRef="Task_1" targetRef="EndEvent_1" />
</bpmn:process>