IBM COBOL

{{Infobox software

| name = IBM COBOL compiler

| logo = IBM OS Full American National Standard COBOL.jpg

| screenshot =

| logo caption = IBM COBOL language manual with OS/VS compiler extensions, 1975

| collapsible =

| developer = IBM

| latest_release_version =

| latest_release_date =

| latest_preview_version =

| latest_preview_date =

| operating_system = Cross-platform

| language = Multilingual

| programming_language =

| genre = Software development

| license = Proprietary

| website = https://www.ibm.com/products/cobol-compiler-family

}}

IBM has offered the computer programming language COBOL on many platforms, starting with the IBM 1400 series and IBM 7000 series, continuing into the industry-dominant IBM System/360 and IBM System/370 mainframe systems, and then through IBM Power Systems (AIX), IBM Z (z/OS and z/VSE), and x86 (Linux).

At the height of COBOL usage in the 1960s through 1980s, the IBM COBOL product was the most important of any industry COBOL compilers. In his popular textbook A Simplified Guide to Structured COBOL Programming, Daniel D. McCracken tries to make the treatment general for any machine and compiler, but when he gives details for a particular one, they are to the IBM COBOL compiler and for a System/370.{{cite book | title=A Simplified Guide to Structured COBOL Programming | publisher=Wiley | year=1976 | isbn=0-471-58284-0 | first=Daniel D. | last=McCracken | pages=1, 7–9, 68–69, 78n, 149 }} Similarly, another popular textbook of the time, Stern and Stern's Structured COBOL Programming, tries to present an implementation-independent explanation of the language, but the appendix giving the full syntax of the language is explicitly for IBM COBOL, with its extensions to the language highlighted.{{cite book | title=Structured COBOL Programming | first1=Nancy | last1=Stern | first2=Robert A. | last2=Stern | publisher=John Wiley & Sons | location=New York | edition=3rd | date=1980 | isbn=0-471-04913-1 | pages=x, 4–5, Appendix E (539–561)}}

Use of IBM COBOL was so widespread that Capex Corporation, an independent software vendor, made a post-code generation phase object code optimizer for it.{{cite news | title=uncertain | work=EDP Analyzer | volume=9–10 | publisher =United Communications Group | date= 1971 | pages=2–3 | url=https://books.google.com/books?id=PdgcAQAAMAAJ&q=%22minimizing+the+number+of+register+load+instructions%22}} The Capex Optimizer became a quite successful product.{{cite news | url=https://books.google.com/books?id=XEToBl0e2NIC&pg=PA23 | title=Users Put 38 Packages on Honor Roll | author-first=Don | author-last=Leavitt | newspaper=Computerworld | date=January 17, 1977 | page=23}}

Although the IBM COBOL Compiler Family web site{{cite web

| title = IBM COBOL Compiler Family

| date = 16 May 2024

| url = https://www.ibm.com/products/cobol-compiler-family

| publisher = IBM

}}

only mentions AIX, Linux, and z/OS, IBM still offers COBOL on z/VM and z/VSE.