Jenkins (DevOps build & deployment orchastration tool)
Git (Source code repository)
Ansible (A tool for provisioning, configuration management, and application-deployment)
Docker (Docker is a tool to create, deploy, and run applications by using virtual container)
ELK Stack (Consists of Elasticsearch, Logstash, and Kibana)
Chef(A configuration management tool for server setup physical/virtual/cloud)
Vagrant (Build tool)
Also refer: What is devops?