Basement has a well-written API which allow developer to add custom theme option and custom “Stack” without touching the core.

    Powerful Stack Builder with tons of pre-defined elements: Blog, Callout, Client, Column, Contact, Features (icon or image), Portfolio (slide or filter), Testimonial and more!
    Developer API which allow you to add custom “Stack” & “Theme Option”
    Responsive Ready
    Retina Display Ready
    Unique Slider with Parallax BG effect
    Custom Module (custom post type): Portfolio, People and Testimonial
    WooCommerce ready. Support 3 page product page layouts (full width / sidebar left / sidebar right)
    MailChimp & Aweber subscribe form integrated
    Custom icon font importer (generate your own icon set at fontello.com)
    Custom Sidebar generator
    Shortcode Generator plugins (compatible with WP 3.9 which use TinyMCE 4.0)
    Dark / Light Header Style
    Unlimited Colors & Fonts
    Code with SEO in Mind
    WPML & Tranlatation Ready (.pot file included)
    Custom 404 page
    Custom Post Type Slug
    Support RTL text direction
    Great support and much more...