INTEGRAL is an optical fiber unit for performing 2D spectroscopy ofextended objects at the 4.2m. William Herschel Telescope (WHT). It is mounted at the GHRIL Nasmyth focus together with newly built acquisition, guiding, and calibration units. It makes use of the specially designed fiber spectrograph WYFFOS. This system allows up to six bundles to be mounted simultaneously. It currently contains three science oriented fiber bundles, any one of which can be easily and quickly placed in the telescope beam. Their spatial resolution elements (fiber core diameters) are O".45, O".9, and 2".T, respectively. Hence, depending on the prevailing seeing conditions the instrument can be easily optimized for the scientific program. INTEGRAL was succesfully commissioned at the WilT during a six night period in July 1997. Here we will discuss its main characteristics.

The Gran Telescopio Canarias (GTC) is a lOm-class telescope which is under construction and will be operational at the Observatorio del Roque de Los Muchachos at the end of 2003. The goal of this paper is to describe the current status of the design and construction of the primary, secondary and tertiary mirrors of the GTC and their opto-mechanical supports. It also summarizes the optical performances expected from the GTC and the error budget of the optical system.The primary mirror is segmented into 36 hexagonal segments. Each segment can be actively deformed to correct figure distortion. In addition, an active stabilization ioop permits the relative position between the segments to be maintained so that they will function as a single optical surface. The GTC will work with a single secondary mirror, which will be used for both visible and infrared observations. Only the system of baffles will be changed between observations in he visible and infrared. The secondary mirror will be a lightweight glass mirror moved by a driving unit with the capability of active alignment and fast tip-tilt correction; the latter function will be used for chopping and image motion correction. The tertiary mirror will permit the light beam to be directed to the Nasmyth and folded-Cassegrain focal stations. A trade-off of several alternatives that we have evaluated will be presented as well the current concept for the mirror and the support.

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