  Decentralized services and applications provide a multitude of advantages for
their users, such as improved privacy, control, and independence from third
parties. Anyhow, decentralization comes at the cost of certain disadvantages,
such as increased application complexity or communication overhead. This
aggravates the development and deployment of decentralized services and
applications. In this paper we present Blade, a software platform that aims to
ease the effort of development, deployment, and administration of decentralized
services by implementing reusable solutions for recurring challenges developers
are facing when designing decentralized service architectures. This includes
functionality for e.g. identity management, access control, request handling,
verification of authenticity and integrity, discovery, or routing. Blade
implements all this functionality in a Blade server instance, which can be
deployed on a lightweight device, such as a NAS, Raspberry Pi, or router at
home. This allows users without expert knowledge to run a Blade instance with
already existing hardware with little overhead. Blade supports polyglot Blade
modules that implement extended functionality, such as interfaces, frontends,
and business logic of decentralized applications, e.g. a decentralized instant
messaging service or an online social network. Based on the Oracle GraalVM,
Blade modules can be implemented in a variety of programming languages and
utilize the functionality provided by the Blade server instance. Blade modules
are published in a Ethereum-based decentralized marketplace from where they can
be installed directly via the Blade instances...
