Learn Spanish (Spain): El software es rápido e intuitivo.

You can use the correlative structure to say: El software es tanto rápido como intuitivo. This adds emphasis to the fact that the program possesses both of these positive qualities equally.

Why is the word e used here instead of the usual y for 'and'?

The conjunction y changes to e whenever the following word starts with an 'i' or 'hi' sound, such as intuitivo. This prevents the awkwardness of pronouncing two 'ee' sounds right next to each other, allowing the spoken sentence to flow much better.

Since software is an English word, how do we know it is masculine?

When English loanwords are adopted into Spanish, they are almost always assigned the masculine gender by default. That is why we say el software and why the adjectives rápido and intuitivo take the masculine -o ending.