  LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer
constructed in the north of the Netherlands and across europe. Utilizing a
novel phased-array design, LOFAR covers the largely unexplored low-frequency
range from 10-240 MHz and provides a number of unique observing capabilities.
Spreading out from a core located near the village of Exloo in the northeast of
the Netherlands, a total of 40 LOFAR stations are nearing completion. A further
five stations have been deployed throughout Germany, and one station has been
built in each of France, Sweden, and the UK. Digital beam-forming techniques
make the LOFAR system agile and allow for rapid repointing of the telescope as
well as the potential for multiple simultaneous observations. With its dense
core array and long interferometric baselines, LOFAR achieves unparalleled
sensitivity and angular resolution in the low-frequency radio regime. The LOFAR
facilities are jointly operated by the International LOFAR Telescope (ILT)
foundation, as an observatory open to the global astronomical community. LOFAR
is one of the first radio observatories to feature automated processing
pipelines to deliver fully calibrated science products to its user community.
LOFAR's new capabilities, techniques and modus operandi make it an important
pathfinder for the Square Kilometre Array (SKA). We give an overview of the
LOFAR instrument, its major hardware and software components, and the core
science objectives that have driven its design. In addition, we present a
selection of new results from the commissioning phase of this new radio
observatory.
