The Most Amazing Development Environment Ever

The latest version of Graham Nelson's Inform compiler for writing interactive fiction (aka text adventure games). By strange coincidence I was just getting back into Trinity (almost finished it) and was toying with playing with interactive fiction myself. This environment seems like a real pleasure to use and to get an idea of why this is so amazing, here is some actual compilable code:

The Dining Car is a room. Lord Peter is a man in the Dining Car. Sherlock Holmes is a man in the Dining Car. Miss Marple is a woman in the Dining Car. Adam Dalgliesh is a man in the Dining Car.

Suspecting relates various people to one person.

The verb to suspect (he suspects, they suspect, he suspected, it is suspected) implies the suspecting relation.

Dalgliesh suspects Holmes. Holmes suspects Lord Peter. Lord Peter suspects Holmes. Miss Marple suspects the player.

Exculpating relates one thing to various people.

The verb to exculpate (it exculpates, they exculpate, it exculpated, he is exculpated) implies the exculpating relation.

The silver bullet exculpates the player. The pipe ash exculpates Holmes. The poison pen letter exculpates Lord Peter. The poison pen letter exculpates Miss Marple. [Poor Dalgliesh. I guess he did it.]

The pipe ash, the letter and the silver bullet are carried.

and here is some more

The Oval Office is a room. Josh and Toby are men in the Oval. A height is a kind of value. 5 foot 11 specifies a height. A person has a height. Josh is 5 foot 8. Toby is 5 foot 10.

Height guessing is an action applying to one thing and one height. Understand "guess [someone] is [height]" as height guessing.

Check height guessing: if the noun is not a person, say "You can only guess the height of people." instead. Carry out height guessing: if the height of the noun is the height understood, say "Spot on!"; if the height of the noun is greater than the height understood, say "No, [the noun] is taller than that."; if the height of the noun is less than the height understood, say "No, [the noun] is shorter than that."

Test me with "guess josh is 6 foot 3 / guess josh is 5 foot 9 / guess josh is 5 foot 3 / guess josh is 5 foot 8".

As one might expect from Graham Nelson, it is fully (dare I say, literarily) documented and the error messages are the most verbose (as in useful and readable) error messages I have ever seen from any compiler.