What were the first LED retrofit lamps? I tried searching, but everything I find is "New LED lamp!", which is the opposite of what I want.
When were they first available? What color temperature were they? How expensive? Efficiency?
It's a mystery to me, and we all should know.

I've seen them advertised as early as 2002 or 2003, but you really had to search for them. They weren't that bright, but IIRC they were capacitive dropper based multi 5mm LED lamps in many colors. White was not a focal point back then either.

I remember seeing my first 120v LED bulb in the wild in May/June 2005. Was a cluster of 5mm LEDs behind a domed cover that has a golfball pattern on it. And yes it was stupidly dim!

When I saw that I was thinking that's there's no way LEDs would be brighter as a 60w incandescent or affordable (LEDtronics are known to overprice their LEDs)! Boy, how wrong I was then! There's LEDs that are as bright as 100w incandescent!

Who knows where LEDs might go in the future and what might replace them. (Could be resurrection of old tech or something yet to be invented/discovered.)

I too remember LED lamps (incandescent retrofit) in the very early 2000's (2003 or thereabouts). They all used a whole bunch of those 5mm LEDs crammed in the envelope of choice (A-shape or reflector) and gave terrible color and intensity, that purply-cold white 5mm LED color and the entire lamp was rated at 1.5w or 2w tops and all of them used a capacitive dropper. Eventually the warm white 5mm LED was invented and quickly went into those lamps, the color was improved but the light output was still only suitable for "accent" lighting and couldnt replace more than a 10w- 15w incandescent. By about 2008 is when I began seeing the high-power chip containing lamps on the market, which was the turning point for LED. My first high power LED retrofit lamp was a GE PAR30 12w in warm white that I bought in late 2008 and cost me $47.00. It still works today, but isn't as efficient as today's offerings

I'm looking for the earliest 60W replacement lamps, I guess.

I dont remember much those, but do remember the 1st integrated stand alone lamps from ~2006

There were ones with 5mm LEDs (the most) and ones with the 1st attempts to make COBs, one i remember in particular is a parallel array of dies inside a clear "standard" 10mm LED package, and some of the bond wires in it were failing

I dont remember much those, but do remember the 1st integrated stand alone lamps from ~2006

There were ones with 5mm LEDs (the most) and ones with the 1st attempts to make COBs, one i remember in particular is a parallel array of dies inside a clear "standard" 10mm LED package, and some of the bond wires in it were failing

That sounds funny! Are they still around?

No for nearly 10 years now...

No for nearly 10 years now...

What about making my own? Is that too impractical?

Building anything out of 5mm LEDs is kids play. And most LED lanterns of the time were indeed not much more than a body (Aluminum or Plastic) with PCB with 5mm LEDs, set Voltage supply and resistors

The one i am talking about was sorta flexible neck desk lamp with the odd LED thing being one component. That you probably can't make the same at home, though you can make an imitation by dipping modern COB's in clear Epoxy in the shape of a scaled up LED dome. But it won't have the mess of bond wires going above the Phosphor like the originals had

Building anything out of 5mm LEDs is kids play. And most LED lanterns of the time were indeed not much more than a body (Aluminum or Plastic) with PCB with 5mm LEDs, set Voltage supply and resistors

The one i am talking about was sorta flexible neck desk lamp with the odd LED thing being one component. That you probably can't make the same at home, though you can make an imitation by dipping modern COB's in clear Epoxy in the shape of a scaled up LED dome. But it won't have the mess of bond wires going above the Phosphor like the originals had

Modern 5mm LEDs also have the wire going above the phosphor.

As far as I know, the first commercially successful LED retrofits for incandescent lamps were made by MARL around 1989.  They consisted of small clusters of red, yellow or green LED chips inside a plastic housing, with a ballast resistor and E10 screw cap, for replacing miniature incandescent indicator lamps.

A few years later, MARL made what was possibly the first mains voltage LED reflector lamp, if I remember rightly it was 1992.  This British-made lamp consisted of a cluster of red 5mm LEDs inside a plastic housing of similar shape to a GLS lamp with a capacitive driver and E27 cap, and intended to replace the red incandescent lamps used in Darkroom safelights.  These were marketed by Kodak for several years and are widely regarded as being the worlds first proper LED retrofit lamp (although in my view, preceded by the technologically similar miniature retrofits).

The next main application for LED retrofits emerged in USA over the period 1993-94, in which linear arrays of 5mm and 3mm LEDs were arranged inside plastic or glass tubes, on a small PCB that also contained a capacitive driver, and equipped with E12 and E17 caps.  These tubular lamps were produced in red and green colours and were sold as long-life and energy saving retrofits for the small tubular incandescent lamps found in American EXIT signs above emergency access doorways and corridors.  Two of the more successful original producers were Wattman and Lumacell.

After that, things stagnated for a number of years until the white LED had been developed.  Starting around 2005 many companies began to build Nichia's cool white 5mm LEDs into GLS and GU10 / MR16 style lamps.  These were the first LED retrofits for general lighting applications.  Osram's Parathom series were among the most advanced at the time.  It wasn't until about 2007 that the first high power versions started to emerge, in which the main body of the LED lamps was made from a metallic casing in order to provide additional heat sinking and thereby allow an increase in power.  Things started to move quickly around this time, with numerous companies filing patents and starting to market such products, but so far as I can tell the first may have been Optiled of Taiwan, who produced the original LED retrofit lamps for Philips.  These developments followed the introduction of the first high power white LED emitters, most notably Hewlett-Packard's Barracuda (later known as Lumileds Luxeon-1) and Cree's XLamp 7090.

The first 25W incandescent replacement was developed by Philips in 2008.  Consuming a whopping 7W for its pitiful 200lm output with a coolish 3100K colour, it used that company's Luxeon Rebel emitters inside.  The selling price in 2008 was around €30.

Philips also achieved the first 40W retrofit in 2009, also the first lamp to use a remote phosphor.  And in 2010 they followed suit with the first 60W retrofit, having a novel mushroom-shaped design and three separate light sources, each with its own remote phosphor shell.  Those retailed for €60 each at the time of launch, but quickly dropped in price as the design was simplified to avoid the expensive remote phosphor construction.

In terms of reflector lamps, the Philips/Optiled PAR16 was the first, in 2006.  It was rated 2W and gave a meagre 50 lumens.  By 2008/2009 Osram and Philips had both increased the output to around 200lm, and in 2010 almost matched the 350lm of a popular 50W reflector lamp, however that needed a huge heatsink and the LED lamp was nearly twice as large as the halogen it was intended to replace.  The first professional LED lamp to replace MR16/GU10 lamps was Sylvania's 350lm small-size RefLED ES50 of 2010, the worlds first LED to match the lumen output of the 50W halogen with an LED retrofit of same dimensions as the halogen original.

Great explanation! I will consider the Osram Parathom the first LED retrofit.