WikiSuite vs Microsoft

WikiSuite can be seen as a FLOSS

Free / Libre / Open Source software

self-hosted alternative to Office 365 and most Microsoft software, to manage your organizational data.
Microsoft WikiSuite
Windows Server ClearOS is an open source alternative to Windows Server. It provides server and networking functions, with many features including mail and messaging (IMAP, POP), content filtering, intrusion protection, antimalware and antispam, and file and print services. The current focus is to add JMAP support.
Active Directory OpenLDAP in ClearOS
Skype and Lync Server-side: Openfire + Converse (XMPP) with Jitsi Meet (WebRTC) Desktop client: Pàdé, a Chrome extension with many features. See Pàdé Presentation phone system: FreeSWITCH & FusionPBX.
Exchange JMAP
OneDrive Tiki File Gallery - Data stored on ClearOS Flexshare and Syncthing for automated file synchronization.
Project Tiki Trackers and other features in Tiki can be configured to be a project management tool for a typical organization (most people use a spreadsheet for project management anyway). New to Tiki19: https://doc.tiki.org/PluginGanttChart
Visio Tiki Diagram (MxGraph / draw.io)
SharePoint Forms: Tiki Trackers, Files: Tiki File Gallery. Tiki is the the most popular alternative to SharePoint on alternativeto.net
SQL Server For end user databases: Tiki Trackers. For a more traditional relational database, use the same as Tiki: MySQL or MariaDB.
Power BI PluginPivotTable and Plotly
Office Tiki Wiki CMS Groupware for most data management as it is the Free/Libre/Open Source Web Application with the most built-in features.
Word Tiki Wiki with or without WYSIWYG
Excel Tiki Spreadsheet
PowerPoint Tiki Slideshow
Access Tiki Trackers
Outlook JMAP
OneNote Tiki Notepad
Publisher Tiki offer very good PDF generation with mPDF and plans/ideas to improve as an Online Publishing House
Visual Studio For End user programming, use the existing feature set in Tiki. Especially Tiki Trackers. JavaScript, jQuery and many other Wiki Plugins can be used. For more advanced use cases, you can use Tiki as Framework or even direct PHP and JavaScript.
Bing We won't do a search of public data, but for all your internal data: Elasticsearch, including Search within files and increasingly some Natural Language Processing (NLP) features.
Dynamics Tiki Trackers can be configured as a CRM, and the mail integration is being work on via JMAP
Yammer Tiki can be configured to make your own Social Networking site.
Windows Lubuntu
System Center not yet, but it's on the radar.
Azure not yet, but it's on the radar.

Other alternatives