The ELK Stack, comprising Elasticsearch, Logstash, and Kibana, has become a leading open-source platform for log management and analysis, widely adopted across various industries. Major companies like Netflix, LinkedIn, and Stack Overflow utilize ELK for diverse purposes such as monitoring IT operations, supporting customer service, analyzing security events, and improving business intelligence. Netflix uses Elasticsearch for its scalability and flexibility, while Stack Overflow employs it to enhance search capabilities. LinkedIn integrates ELK with Kafka for real-time performance monitoring, and Fujitsu leverages it to analyze OpenStack cloud logs. Accenture prefers ELK over proprietary alternatives like Splunk for its simplicity and extensibility, while companies like Tripwire and Medium use it for security information event management and debugging production issues, respectively. Additionally, platforms such as Swat.io, IFTTT, and HipChat rely on ELK for real-time monitoring and scalability, illustrating the stack's versatility in addressing various business needs.