Solo5 is a microkernel friendly, sandboxed, re-targetable execution environment for unikernels, with a taste for minimalism. We will start with an overview of core Solo5 concepts and present the interfaces it offers to the unikernel/library operating system/application developer. Using existing library operating systems, such as MirageOS, we will demonstrate the developer experience for various Solo5 targets, going on to show how rigorously applying minimalist principles to interface design is used to our advantage, blurring traditional lines between unikernels, processes, kernels and hypervisors. We will conclude with some lessons learned during development of Solo5 thus far, and present ideas and challenges for future development. The target audiences for this talk are application developers with an interest in operating systems and unikernels, language runtime and toolchain developers interested in porting their language to a unikernel environment such as Solo5, and operating systems developers in general. No {uni,micro,separation,monolithic,}kernels or hypervisors will be harmed during this talk.