Pros of CAS

• Focused on authentication and single sign-on, providing a specialized solution
• Highly extensible and customizable with a plugin architecture
• Supports a wide range of authentication protocols and integrations

Cons of CAS

• Limited in scope compared to Canvas LMS's full learning management system
• May require additional components for a complete educational platform
• Steeper learning curve for non-authentication-focused developers

Code Comparison

CAS (Java):

@Bean
public AuthenticationHandler myAuthenticationHandler() {
    return new MyCustomAuthenticationHandler();
}

Canvas LMS (Ruby):

class MyAuthenticationProvider < Canvas::Authentication::Provider
  def authenticate(username, password)
    # Custom authentication logic
  end
end

Both projects allow for custom authentication handlers, but CAS uses Java annotations and Spring framework, while Canvas LMS uses Ruby classes and inheritance.

CAS focuses on providing a robust authentication framework with extensive customization options, whereas Canvas LMS offers a complete learning management system with built-in authentication as part of its broader feature set. CAS is ideal for organizations needing a dedicated SSO solution, while Canvas LMS is better suited for educational institutions requiring a full-featured LMS platform.

Pros of Moodle

• More extensive plugin ecosystem with thousands of community-contributed extensions
• Highly customizable and flexible for diverse educational needs
• Stronger support for multilingual environments and localization

Cons of Moodle

• Steeper learning curve for administrators and instructors
• User interface can be less intuitive and modern compared to Canvas
• Performance may suffer with heavy customizations or large-scale deployments

Code Comparison

Moodle (PHP):

function get_course_module_from_cmid($cmid) {
    global $DB;
    return $DB->get_record_sql("
        SELECT cm.*, m.name AS modname
          FROM {course_modules} cm
          JOIN {modules} m ON m.id = cm.module
         WHERE cm.id = ?", array($cmid));
}

Canvas LMS (Ruby):

def get_course_module(module_id)
  ContentTag.find_by(id: module_id)
    .try(:context_module)
    .try(:content_tags)
    .try(:active)
    .try(:preload, :content)
end

Both repositories showcase different approaches to retrieving course module information, reflecting their respective programming languages and database structures. Moodle's code demonstrates a more direct SQL query approach, while Canvas LMS utilizes ActiveRecord methods for object-relational mapping.

Pros of Oppia

• Open-source and community-driven, allowing for greater customization and contributions
• Focuses on interactive, exploratory learning experiences
• Designed for creating engaging educational content with a user-friendly interface

Cons of Oppia

• Smaller user base and community compared to Canvas LMS
• More limited in scope, primarily focused on creating interactive lessons rather than full course management
• Less extensive documentation and support resources

Code Comparison

Canvas LMS (Ruby):

def update
  @context = api_find(Course, params[:course_id])
  @assignment = @context.assignments.find(params[:id])
  @assignment.update_attributes(params[:assignment])
end

Oppia (Python):

def update_exploration(exploration_id, change_list):
    exploration = get_exploration_by_id(exploration_id)
    try:
        exploration.update_from_changelist(change_list)
    except Exception as e:
        raise self.InvalidInputException(e)

Both repositories use different programming languages and have distinct architectures. Canvas LMS is built with Ruby on Rails, while Oppia uses Python. The code snippets show different approaches to updating content, with Canvas focusing on assignment updates and Oppia handling exploration updates through changelists.