The creators of the BlackCat ransomware offer Ransomware-as-a-Service (RaaS). In other words, they allow other cybercriminals to access their infrastructure and malicious code in exchange for a certain percentage of the ransom. On top of that, it's highly likely that members of the BlackCat group are responsible for negotiating with victims.
BlackCat's arsenal includes several elements. The first is an encryption tool of the same name. It is coded in Rust, which allowed the cybercriminals to create a cross-platform tool with versions of the malware that run on Windows and Linux.