I love good ol HTML5/CSS, because you have more control over your code. BUT if you're short on time and you need to whip up a website fairly quickly Bootstrap is a great framework. Learning its class's and id's are the hardest part (which is pretty easy if you have their website pulled up). JQuery UI and Mobile are great tools because they have unlimited plugins you can utilize, they're also interactive. TextWrangler is a great FREE editor I use everyday. it's simple and did I mention FREE. All of these downloads are responsive and can stack multiple plugins. They make my designing experience fun. Thank you smart developers!!