The objective of EXCELERATE Deliverable 1.5 is to review software metrics and assess their usefulness in the context of the bio.tools (https://bio.tools) registry, with view to expose in bio.tools, metrics from scientific performance benchmarking, technical monitoring, and of software or service quality in general. The core aim is to provide the end-user with robust, scientifically relevant measures of quality and performance, to guide them in their comparison and selection of tools through: 1) enabling end-users to sort and filter bio.tools search results by various criteria, and 2) to render labels on bio.tools Tool Cards, perhaps even (eventually) a formal ELIXIR quality stamp. This deliverable report describes research into the problem and implementation of prototype solutions towards the stated objectives and core aim. This report describes work done with ELIXIR-EXCELERATE resources.