I was doing a bit of housekeeping on my web site recently and came across the reviews I’d written for the original Lightroom Public beta dating back to January 2006. Further digging around turned up reviews for all the versions since. So, for a bit of reminiscing and to make them easier to find, I’ll provide a link to each of the Public Beta’s and major versions below.
A public beta was a significant break in tradition for Adobe in that it was the first time that the company publicly showed a product to potential customers in an unfinished state. Nevertheless, giving customers access to Lightroom at such an early stage in its development worked well and generated such enthusiasm amongst customers that Adobe would later adopt the idea for products such as Photoshop.
So, how much has changed in the intervening 17 years? Well, a good place to start a comparison would be the User Interface.

Library Module – Lightroom Public Beta 1, January 2006

Library Module – Lightroom Classic 12, January 2023
On the face of it, the basic principles and modular layout are broadly similar in appearance. However, the feature set in 2023 far exceeds the customer expectations of 2006. To see what else has changed or been improved upon since see my reviews at below links.
Lightroom Public Beta 1 – January 2006
Lightroom Public Beta 3 for Windows – Up to this point Lightroom was only available on the Mac Platform.
Lightroom Public Beta 4 – the public aspect of the beta programme finished at this point, but Adobe now started to implement much of the feedback they’d received during the public beta phase.
Lightroom 1.0 – No review but reason explained in 1.1 Update below
Lightroom 6 (aka CC 2015) – the version where Adobe decided it was time to confuse customers with a new name and fist introduction of subscription.
Lightroom Classic CC – another new name to confuse customers. This is also first of the annual updates also marked the beginning of reduction in number of new features.
Camera Support in Lightroom Classic
Details of new camera support added since the last release can be found here
Lens Correction Support in Lightroom Classic
Details of new lens support added since the last release can be found here
Disclosure: As an Adobe Community Expert I receive a free subscription to Adobe Creative Cloud.