Splash, the latest theme from 1LD is an unusual, two-headed beast that's half modular framework, half theme.

According to the website, each Modular theme comes with a specialized theme Stack. The first of these is Splash which arrives with one theme stack and three Modular stacks: Condition, Section and Slider.
Building a Modular site involves a Header page with theme stacks. One or more Splash Theme stacks are inserted into the Header page. If you have ten pages, you may have a single Splash stack which will then display on every page, or you can add ten Splash/Condition stacks; one for each page. The Condition stacks contain instructions for inserting each header from the header page into the appropriate content page.
In a similar fashion, you also need to add a Footer page. The content from the footer page is then automatically added to every page of your project.

The content pages may be either standard RW pages, or Stacks pages into which you can add any content of your choice, including the Section and Slider stacks that come with the theme. The Section stack is a full width stack by default. The content width and the content colours are defined within the stack settings.
The Slider stack is a nice slider in which the transition (29 options) for each image is set individually. The use of the Slider stack is not confined to the Modular themes, which is great news.
When you view your preview, you can click the button that appears at the foot of the page to load the partials – i.e. the header and the footer.

Splash itself is an interesting theme that many will like. It has an animated wave below the Header and a blue-black footer (editable in the Splash stack). The header can be set to any colour you please including gradients or images with, or without a colour overlay and stacks. The header will also display the Slider stack.
The Splash theme automatically adds two menus – a centred menu bar without dropdowns and a floating hamburger menu that displays all your project pages including submenus.
Splash is delivered with a demo project and with a starter project. It's advisable to duplicate the starter project and use it as a basis for your new webpages.

Stack settings
Splash – Contains all of the settings for your project page including all colours and fonts.
Condition – Show – only on specific pages (comma separated list), on all pages except (comma separated list).
Section – Content Width, Colours, Section ID, Section Class
Slider – Image Alignment, Slider Height (%), Slider Hang Time, Transition Time, Autoplay, Show Navigation only on Hover, Show Bar Timer, Slider Colours

The modular build of Splash is an interesting concept, especially for the less experienced Weaver. It doesn't have the steep learning curve that some frameworks have; it can be used with standard RW pages or with Stacks pages, but it is flexible enough to build even the most complicated page.
I look forward to seeing more modular themes from 1LD.