From the data given: Altera is the major rival to Xilinx for the FPGA market. To compete with the Spartan-3 series, Altera developed the Cyclone II FPGA line (theyre up to Cyclone V, and have apparently skipped to Cyclone 10 now.). Search the web for the low end Cyclone II EP2C5 and compare its features to those of the Xilinx Spartan-3E XC3100E.

Some of the features you might look at include gate count, number of LUTs (and number of inputs to each LUT), numbers of multipliers, clock speed if available, etc.)

Note that Alteras name for a LUT is a Logic Element (LE), which doesnt quite correspond to a LUT but its close.

(Hint: dont get crazy about thisyou dont have to track down all the parameters listed above, just a few should tell you if its better, about as good as, or worse than the Xilinx device. A first-order approximation is just the number of flip-flops and amount of RAM.)