The best ODE (Oridinary Differential Equations) textbook that I have ever used...and I tried several. The author does a brilliant job explaining and helping you to understand the subject...not just do problems. Howell does not skip important steps in developing the material. Proofs are not presented as terse little demonstatrations of the author's cleverness... instead his proofs are well fleshed out, understandable and serve to enlighten and help you better understand the material. The treatment is serious and rigorous, but unlike other texts, I felt like I understood the subject, not just able to pass a test. And thank God, the author has a since of humour...this is evidenced by his invitation to get comfortable with Euler's equation and complex numbers. Frankly, this textbook is responsible, in no small way, for why I am in graduate studies in applied mathematics today. Mathematics is so much more meaningful & enjoyable when you understand it. Its perfect for applied math, engineers and computer scientists in AI. There are a lot of very bad math textbooks out there...but this is NOT one of them. So 5-stars for a math text? Yeah, I know, right? But well deserved.