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NS2 File - What is an .ns2 file and how do I open it?
Learn about .NS2 files and view a list of programs that open them.
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Overview
What is an NS2 file? An NS2 file is a database used by version 2 of IBM Lotus Notes, a collaborative client-server platform for email, messaging, and business applications. It stores structured information in the Notes database format, such as contact lists, calendars, address books, discussion databases, notes, and other data that Lotus Notes applications share. NS2 files were replaced by .NSF file that later versions of Lotus Notes used.
More Information Lotus Development Corporation released version 2 of Lotus Notes in 1991, introducing the NS2 format. During the 1990s, organizations that implemented Lotus Notes used NS2 databases to manage information and collaborate with other Lotus Notes users across a network. However, as new versions of Lotus Notes were released, the NS2 format has become obscure. NOTE: IBM acquired Lotus Development Corporation in 1995, and then IBM sold the company (now known as "Lotus Software") to HCL Technologies in 2018. Lotus Notes is now known as "HCL Notes."
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.NS2 File Extension
Lotus Notes 2 Database
| Developer | IBM |
| Popularity |
2.5 | 4 Votes |
What is an NS2 file?
An NS2 file is a database used by version 2 of IBM Lotus Notes, a collaborative client-server platform for email, messaging, and business applications. It stores structured information in the Notes database format, such as contact lists, calendars, address books, discussion databases, notes, and other data that Lotus Notes applications share. NS2 files were replaced by .NSF file that later versions of Lotus Notes used.
More Information
Lotus Development Corporation released version 2 of Lotus Notes in 1991, introducing the NS2 format. During the 1990s, organizations that implemented Lotus Notes used NS2 databases to manage information and collaborate with other Lotus Notes users across a network. However, as new versions of Lotus Notes were released, the NS2 format has become obscure.
NOTE: IBM acquired Lotus Development Corporation in 1995, and then IBM sold the company (now known as "Lotus Software") to HCL Technologies in 2018. Lotus Notes is now known as "HCL Notes."
How to open an NS2 file
You can open NS2 files with IBM Lotus Notes. However, the software is discontinued.
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Programs that open NS2 files
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IBM Lotus Notes 2
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Paid
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IBM Lotus Notes 2
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Discontinued
Paid
Category: Database Files
Updated: March 5, 2026