A host of new technologies are competing to make tube-driven televisions obsolete. Here are three leading candidates:

• Plasma. These panels consist of two glass sheets sandwiching an array of tiny electrodes and phosphors, which emit colored light when ignited by current passing through the electrodes. The sets are thin — less than 4 inches deep — and light enough to hang on a wall, although they must be wired to a separate receiver to tune in TV signals. Screen sizes range from 34 inches to 63 inches diagonally, and screen resolution ranges from high-definition TV, with 720 horizontal lines displayed on screen, to something closer to DVD quality, at 480 lines. Prices start at $3,000 for a 42-inch screen.
• Liquid crystal. These displays use a semisolid substance encased in glass to filter beams of light into thousands of tiny points of color. They’re thinner and lighter than plasma displays, and they tend to last three times as long. But they’re smaller and may have some lingering performance problems, including poor picture quality when viewed from a sharp angle and less clarity on fast-moving pictures. Most units have screen sizes between 15 inches and 22 inches, with screen resolution in the same range as plasma. Some units have built-in analog TV receivers. Prices start at $650 for a 17-inch unit.
• Digital light processing. These sets bounce beams of light off microscopic, electronically powered mirrors. Thicker and heavier than LCDs or plasma displays, DLP sets can’t hang on a wall, but they can be slimmer than competing projection TVs. Most come equipped with an analog TV receiver. Screen sizes run from 43 inches to 65 inches, typically with high-definition resolutions (720 lines). Prices start around $3,700 for a 43-inch unit.