Mobile Information Device Profile (MIDP) is a specification published for the use of Java on embedded devices such as mobile phones and PDAs. MIDP is part of the Java Platform, Micro Edition (Java ME) framework and sits on top of Connected Limited Device Configuration (CLDC), a set of lower level programming interfaces. MIDP was developed under the Java Community Process. The first MIDP devices were launched in April 2001.

The core application programming interfaces are defined by the underlying Connected Limited Device Configuration system.

Contains the Java ME-specific classes used for I/O operations.

Contains the Java ME-specific classes used for the GUI.

LCDUI has a simple screen based approach where a single Displayable is always active at anyone time in the application user interface. LCDUI API provides a small set of displayables common in mobile device user interfaces: List, Alert, TextBox, Form and Canvas. For all displayables the device MIDP implementation has control over the presentation and layout of the displayable. Canvas is a low-level graphics surface for which an application has full control over what is rendered to it, although normally some space is reserved for system areas like screen title and indicators common in mobile device UIs. Since MIDP 2.0, Canvas also supports a full-screen mode that allows use of full screen graphics, which is especially useful for games.

LCDUI also has a quite unique approach of abstract operations, called Commands. The placement of commands added to a displayable is completely up to the device implementation of this toolkit. The application programmer uses API specified command types to indicate the usage or purpose of the command in an application user interface. Common types are BACK, EXIT, ITEM, SCREEN. The idea of the command abstraction is to make applications more portable across various mobile devices. Application developers should use the command types properly to indicate the purpose of an operation, and device implementation then places the operation to the common location for a given type in a device's specific user interface style. This may be e.g. a specific key, like "a back navigation key" for BACK commands or a button on screen.

The acronym LCDUI was actually an in-house joke within the JCP Expert Group. Though undefined in the MIDP specifications, it denotes Limited Capability Device User Interface. (The joke was that no one else really knew what it stood for). Later, the book Programming Wireless Devices with the Java 2 Platform, Micro Edition gave this as the definition.

Other common pseudo-definitions have appeared. "Liquid Crystal Display User Interface" would reflect the fact that mobile phones normally use LCDs; however, the API is not specifically tailored to this particular display technology. It is also said that "LCD UI" stands for "lowest common denominator" due to the fact the specific UI has the simplest possible design.