What Is jms.jar? I heard it's related to JMS (Java Message Service) 1.1?

The if you have an jms.jar file of 25998 bytes, it is the JAR file of the Sun implementation version 1.1 of the JMS (Java Message Service) 1.1 specification.

JAR File Size and Download Location:

JAR name: jms.jar, jms-1.1.jar
Target JDK version: 1.1
File name: jsm.jar
File size: 25998 bytes
Release date: 30-Apr-2002
Download: Oracle JMS Download

Manifest of the JAR: None

List of Classes in the JAR:

javax/jms/BytesMessage
javax/jms/Message
javax/jms/JMSException
javax/jms/Destination
javax/jms/DeliveryMode
javax/jms/Connection
javax/jms/Session
javax/jms/ConnectionMetaData
javax/jms/ExceptionListener
javax/jms/ServerSessionPool
javax/jms/ConnectionConsumer
javax/jms/Topic
javax/jms/MapMessage
javax/jms/ObjectMessage
javax/jms/StreamMessage
javax/jms/TextMessage
javax/jms/MessageListener
javax/jms/MessageProducer
javax/jms/MessageConsumer
javax/jms/Queue
javax/jms/TopicSubscriber
javax/jms/QueueBrowser
javax/jms/TemporaryQueue
javax/jms/TemporaryTopic
javax/jms/ServerSession
javax/jms/ConnectionFactory
javax/jms/MessageNotReadableException
javax/jms/MessageNotWriteableException
javax/jms/QueueConnection
javax/jms/QueueSession
javax/jms/QueueReceiver
javax/jms/QueueSender
javax/jms/QueueConnectionFactory
javax/jms/QueueRequestor
javax/jms/TopicConnection
javax/jms/TopicSession
javax/jms/TopicPublisher
javax/jms/TopicConnectionFactory
javax/jms/TopicRequestor
javax/jms/XAConnection
javax/jms/XASession
javax/jms/XAConnectionFactory
javax/jms/XAQueueConnection
javax/jms/XAQueueSession
javax/jms/XAQueueConnectionFactory
javax/jms/XATopicConnection
javax/jms/XATopicSession
javax/jms/XATopicConnectionFactory
javax/jms/MessageEOFException
javax/jms/TransactionRolledBackException
javax/jms/MessageFormatException
javax/jms/IllegalStateException
javax/jms/JMSSecurityException
javax/jms/ResourceAllocationException
javax/jms/TransactionInProgressException
javax/jms/InvalidDestinationException
javax/jms/InvalidClientIDException
javax/jms/InvalidSelectorException