Linux on SPARC: 2 kernels. Actually Linux on SPARC architecture comes in two flavors: A 32 bits kernel for the Sun SPARC, Super SPARC, Micro SPARC and Hyper SPARC Processors. A 64 bits kernel for UltraSPARC based computers. In both case most applications run in 32 bit ( 32 bit userland ). There is a comprehensive FAQ on UltraLinux's website.

What distro Linux for Sparc? Apr 17, 2003 Oracle Linux SPARC UEK May 26, 2017

Aurora SPARC Linux Project

DistroWatch.com: Put the fun back into computing. Use Gentoo Linux is a versatile and fast, completely free Linux distribution geared towards developers and network professionals. Unlike other distros, Gentoo Linux has an advanced package management system called Portage. Solaris is written in a platform-independent manner and is available for SPARC and x86 processors (including x86_64 DownloadOther – BOINC

SPARC (Scalable Processor Architecture) is a 32- and 64-bit microprocessor architecture from Sun Microsystems that is based on reduced instruction set computing ( RISC ). SPARC has become a widely-used architecture for hardware used with UNIX -based operating systems, including Sun's own Solaris systems. Sun has made SPARC an open architecture

SPARC M8 Processors Launched - Phoronix Sep 18, 2017 Migrating from SPARC to x86 - Tech Remember the SPARC Vs. x86 post I made some time ago? I've talked about sizing old SPARC hardware compared to new x86 based servers. Well, I have just finished a rather big project migrating several single-instance Oracle 8i databases running on old(ish) SPARC machines to a state of the art Oracle 10g RAC on commodity x86 Linux servers. Ellison: Oracle Enterprise Linux coming to Sparc