Editing Linear Tape-Open (section)

== Historical context ==
{{Memory types}}

Half-inch (12.65&nbsp;mm) wide magnetic tape has been used for data storage since the 1950s, starting with the open reel formats [[IBM 7-track]] and later [[9-track tape|IBM 9-track]].

In the mid-1980s, smaller, enclosed, single-reel cartridge formats were developed by [[IBM]] and [[Digital Equipment Corporation|DEC]]. Although the physical tape was nominally the same width in these new formats and the preceding open-reel formats, the technologies and intended markets were significantly different and there was no compatibility between them. The [[IBM 3480 family|IBM 3480]] tape format was designed to meet the demanding requirements of its mainframe products. DEC's CompacTape was targeted at a broader market, including minicomputers and smaller systems.
Later on, it was renamed [[Digital Linear Tape]] (DLT) and eventually sold to [[Quantum Corporation]].

In the late 1980s, Exabyte's [[Data8]] format, derived from Sony's dual-reel cartridge 8&nbsp;mm video format, saw some popularity, especially with UNIX systems. Sony followed this success with their own now-discontinued 8&nbsp;mm data format, [[Advanced Intelligent Tape]] (AIT).

By the late 1990s, Quantum's DLT and Sony's AIT were the leading options for high-capacity tape storage for PC servers and UNIX systems. These technologies were tightly controlled by their owners and consequently, there was little to no competition between vendors and the prices were relatively high.

=== Birth of LTO ===
Seeing an opportunity, IBM, HP and [[Seagate Technology|Seagate]] formed the LTO Consortium,<ref>{{Cite web |title=LTO Ultrium: Reliable and Scalable Open Tape Storage Format |url=https://www.lto.org/ |access-date=2022-10-29 |website=Ultrium LTO |language=en-US}}</ref> which introduced a more open format focusing on the same mid-range market segment.<ref name="Ultrium announcement" /> Much of the technology is an extension of the work done by IBM at its Tucson lab during the previous 20 years.<ref name="IBM storage history" />

In 2000, and around the time of the release of LTO-1, Seagate's magnetic tape division was spun off as Seagate Removable Storage Solutions,<ref>{{Cite web |title=Seagate Removable Storage Solutions Holdings: No Action, Interpretive and/or Exemptive Letter of March 7, 2003 |url=https://www.sec.gov/divisions/corpfin/cf-noaction/seagate030703.htm |access-date=2022-10-29 |website=www.sec.gov}}</ref> later renamed [[Certance]], which was subsequently acquired by Quantum.<ref>{{Cite web |last=Mearian |first=Lucas |date=2004-10-22 |title=Quantum buys Certance for $60M |url=https://www.computerworld.com/article/2567230/quantum-buys-certance-for--60m.html |access-date=2022-10-29 |website=Computerworld |language=en}}</ref>

==== Unrealized variations ====
Initial plans called for two distinct LTO formats:
# Ultrium - with half-inch tape on a single reel, optimized for high capacity, and 
# Accelis<ref name="Licensing" /> - with 8&nbsp;mm tape on dual reels, optimized for fast access.

Despite the initial plans, only Ultrium was ever produced. So, in common usage, LTO refers to just the Ultrium form factor.

Another proposed variation was to have different length tapes. The first generation of Ultrium was going to be available with four types of cartridges, holding 10&nbsp;GB, 30&nbsp;GB, 50&nbsp;GB, and 100&nbsp;GB. However, only the full length 100&nbsp;GB tapes were ever produced.<ref name="EMTEC" />