Answer the following question: Information: - Ian Jackson is a long time free software author and Debian developer . Jackson wrote dpkg ( replacing a more primitive Perl tool with the same name ) , SAUCE ( Software Against Unsolicited Commercial Email ) , userv and debbugs . He used to maintain the Linux FAQ . He runs chiark.greenend.org.uk , a popular server , home to PuTTY among other things . Jackson has a PhD in Computer Science from Cambridge University . He currently works for Citrix and previously worked for Canonical Ltd. and nCipher Corporation . Jackson became Debian Project Leader in January 1998 , before Wichert Akkerman took his place in 1999 . Debian GNU / Linux 2.0 ( hamm ) was released during his term . Jackson was vice-president and then president of Software in the Public Interest in 1998 and 1999 . He was a member of the Debian Technical Committee until November 2014 . - Computer software, or simply software, is that part of a computer system that consists of encoded information or computer instructions, in contrast to the physical hardware from which the system is built. - Open-source software (OSS) is computer software with its source code made available with a license in which the copyright holder provides the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. According to scientists who studied it, open-source software is a prominent example of open collaboration. - Debbugs is the software powering the Debian project's issue tracking system. A unique aspect is that it doesn't have any form of web-interface to edit bug reports - all modification is done through email. Debbugs was mainly written by Ian Jackson, former Debian project leader. - The Linux kernel is a monolithic Unix-like computer operating system kernel. The Linux operating system is based on this kernel and deployed on both traditional computer systems such as personal computers and servers, usually in the form of Linux distributions, and on various embedded devices such as routers, wireless access points, PBXes, set-top boxes, FTA receivers, smart TVs, PVRs and NAS appliances. The Android operating system for tablet computers, smartphones and smartwatches is also based atop the Linux kernel. While the adoption on desktop computers is low, Linux-based operating systems dominate nearly every other segment of computing, from mobile devices to mainframes. , all but two of the world's 500 most powerful supercomputers run Linux. The other two run AIX on IBM power 7 hardware. - sed ("stream editor") is a Unix utility that parses and transforms text, using a simple, compact programming language. sed was developed from 1973 to 1974 by Lee E. McMahon of Bell Labs, and is available today for most operating systems. sed was based on the scripting features of the interactive editor ed ("editor", 1971) and the earlier qed ("quick editor", 196566). sed was one of the earliest tools to support regular expressions, and remains in use for text processing, most notably with the substitution command. Other options for doing "stream editing" include AWK and Perl. - Debian is a Unix-like computer operating system that is composed entirely of free software, most of which is under the GNU General Public License and packaged by a group of individuals participating in the Debian Project. - An issue tracking system (also ITS, trouble ticket system, support ticket, request management or incident ticket system) is a computer software package that manages and maintains lists of issues, as needed by an organization. Issue tracking systems are commonly used in an organization's customer support call center to create, update, and resolve reported customer issues, or even issues reported by that organization's other employees. A support ticket should include vital information for the account involved and the issue encountered. An issue tracking system often also contains a knowledge base containing information on each customer, resolutions to common problems, and other such data. An issue tracking system is similar to a "bugtracker", and often, a software company will sell both, and some bugtrackers are capable of being used as an issue tracking system, and vice versa. Consistent use of an issue or bug tracking system is considered one of the "hallmarks of a good software team". - GNU is an operating system and an extensive collection of computer software. GNU is composed wholly of free software, most of which is licensed under the GNU Project's own GPL. - Linux (pronounced or, less frequently) is a Unix-like computer operating system assembled under the model of free and open-source software development and distribution. The defining component of Linux is the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. The Free Software Foundation uses the name GNU/Linux to describe the operating system, which has led to some controversy. - In physics, heat is that amount of energy flowing from one body to another spontaneously due to their temperature difference, or by any means other than through work or the transfer of matter. The transfer can be by contact between the source and the destination body, as in conduction; or by radiation between remote bodies; or by conduction and radiation through a thick solid wall; or by way of an intermediate fluid body, as in convective circulation; or by a combination of these. - An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require an operating system to function. - Putty is a generic term for a material with high plasticity, similar in texture to clay or dough, typically used in domestic construction and repair as a sealant or filler. Painter's Putty is typically a linseed oil-based product used for filling holes, minor cracks and defacements in wood only. Putties can also be made intumescent, in which case they are used for firestopping as well as for padding of electrical outlet boxes in fire-resistance rated drywall assemblies. In the latter case, hydrates in the putty produce an endothermic reaction to mitigate heat transfer to the unexposed side. - The GNU General Public License (GNU GPL or GPL) is a widely used free software license, which guarantees end users the freedom to run, study, share and modify the software. The license was originally written by Richard Stallman of the Free Software Foundation (FSF) for the GNU Project, and grants the recipients of a computer program the rights of the Free Software Definition. The GPL is a copyleft license, which means that derivative work can only be distributed under the same license terms. This is in distinction to permissive free software licenses, of which the BSD licenses and the MIT License are widely used examples. GPL was the first copyleft license for general use. - Unix (trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, developed starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. - Drywall (also known as plasterboard, wallboard, gypsum panel, sheet rock, or gypsum board) is a panel made of calcium sulfate dihydrate (gypsum) with or without additives and normally pressed between a facer and a backer. It is used to make interior walls and ceilings. Drywall construction became prevalent as a speedier alternative to traditional lath and plaster. - Linus Benedict Torvalds (born December 28, 1969) is a Finnish software engineer who is the creator and, for a long time, principal developer, of the Linux kernel; which became the kernel for operating systems such as the Linux operating system, Android and Chrome OS. He also created the distributed revision control system Git and the diving logging and planning software Subsurface. He was honored, along with Shinya Yamanaka, with the 2012 Millennium Technology Prize by the Technology Academy Finland "in recognition of his creation of a new open source operating system for computers leading to the widely used Linux kernel". He is also the recipient of the 2014 IEEE Computer Society Computer Pioneer Award. - Free software, freedom-respecting software, or software libre is computer software distributed under terms that allow the software users to run the software for any purpose as well as to study, change, and distribute the software and any adapted versions. Free software is a matter of liberty, not price: users, individually or collectively, are free to do what they want with it, including the freedom to redistribute the software free of charge, or to sell it, or charge for related services such as support or warranty for profit. - The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on 4 October 1985 to support the free software movement, which promotes the universal freedom to study, distribute, create, and modify computer software, with the organization's preference for software being distributed under copyleft ("share alike") terms, such as with its own GNU General Public License. The FSF was incorporated in Massachusetts, USA, where it is also based. - Free and open-source software (FOSS) is computer software that can be classified as both free software and open-source software. That is, anyone is freely licensed to use, copy, study, and change the software in any way, and the source code is openly shared so that people are encouraged to voluntarily improve the design of the software. This is in contrast to proprietary software, where the software is under restrictive copyright and the source code is usually hidden from the users. After reading the paragraphs above, we are interested in knowing the entity with which 'ian jackson' exhibits the relationship of 'occupation'. Find the answer from the choices below. Choices: - author - commercial - computer - construction - editor - engineer - general - leader - model - painter - physics - programming - research
Answer:
engineer